| Sacramento Valley | |
|---|---|
Sacramento | |
The Central Valley of California | |
| Geography | |
| Location | California, United States |
| Population centers | Redding,Chico,Yuba City,Sacramento |
| Borders on | Sierra Nevada (east),Cascade Range,Klamath Mountains (north),Coast Range (west),Sacramento–San Joaquin River Delta (south) |
| Coordinates | 39°00′N121°30′W / 39°N 121.5°W /39; -121.5 |
| Rivers | Sacramento River |
TheSacramento Valley is the area of theCentral Valley of theU.S. state ofCalifornia that lies north of theSacramento–San Joaquin River Delta and is drained by theSacramento River. It encompasses all or parts of tenNorthern California counties. Although many areas of the Sacramento Valley are rural, it contains several urban areas, including the state capital,Sacramento.
Comparatively water-rich relative to the other segment of the Central Valley to the south, theSan Joaquin Valley, there are slight differences in the crops typically grown in the Sacramento Valley. Much wetter winters (averaging between 25–60 inches (640–1,520 mm) of annual precipitation in the nearby foothills) and an extensive system of irrigation canals allows for the economic viability of water-thirsty crops such asrice androotstock walnuts. Since 2010, statewidedroughts in California (combined with unprecedented summer heat) have strained both the Sacramento Valley's and the Sacramento metropolitan region'swater security.[1]
TheSacramento River and itstributaries are a significant part of the geography of the Sacramento Valley. Rising in the various mountain ranges (the variousNorthern Coast Ranges to the west, the southernSiskiyou Mountains to the north, and the northernSierra Nevada to the east) that define the shape of thevalley, they provide water for agricultural, industrial, residential, and recreation uses. Most of the rivers are heavily dammed and diverted. In more recent years, statewidedroughts in California have further strained the Sacramento Valley'swater security.[1]

The terrain of the Sacramento Valley is primarily flatgrasslands that become lusher as one moves east from therain shadow of the Coast Ranges toward the Sierra. Unlike the San Joaquin Valley, which in its pre-irrigation state was a vegetation-hostile desert, the somewhat less arid Sacramento Valley had significant tracts of forest prior to the arrival of settlers of European ancestry. Most of it was cut down during theCalifornia Gold Rush and the ensuing wave of American settlement, although there are still some heavily tree-populated areas, such as the greater Sacramento area.
Foothills become more common from just south ofCorning toShasta Lake City. These are known as the Valley Hills and begin south of the Tehama-Glenn County line near Corning. There are also a few hills inRed Bluff and Corning. There is one major range of foothills between Cottonwood and Red Bluff known as the Cottonwood Hills (a.k.a. 9-mile Hill), and there is the Cottonwood Ridge between Anderson and Cottonwood. There are some hills in Redding, a few more than Red Bluff, and north of Redding it is mainly foothills.
One distinctive geographic feature of the Sacramento Valley is theSutter Buttes. Nicknamed the smallest mountain range in the world, it consists of the remnants of an extinctvolcano and is located just outsideYuba City, 44 miles (71 km) north of Sacramento.

Citrus andnutorchards andcattle ranches are common to both halves of the Central Valley. The Sacramento Valley's agricultural industry also resembles that of theSan Joaquin Valley to the south. Nuts, such asalmonds andwalnuts, are of greater importance north of the Delta, andrice, nonviable in the drier San Joaquin Valley, is a major crop. While the region is wetter, soils are somewhat poorer in the Sacramento Valley; this means some crops, particularly vegetables, are less profitable compared to the San Joaquin Valley. The Sacramento Valley is also not as extensively cultivated; there are many moresmallholdings and more uncultivated arable land compared to south of the Delta.
The town ofCorning produces olives for oil extraction and for consumption as fruit. TheSunsweet Growers Incorporated headquarters are inYuba City. The valley controls more than two-thirds of the worldwideprune market through the over 400 growers in California.[2]
Weather patterns in the Sacramento Valley are very similar to those in theSan Joaquin Valley to the south, although the humidity and precipitation tend to be a bit higher. Summers are the dry season, with average daytime temperatures in the low to high 90s °F (low to mid 30s °C) but triple digits (38 °C and above) are a common occurrence, especially inChico,Redding,Red Bluff, andSacramento. Redding in particular has been notorious for having extremely hot summers despite its northern latitude within the United States,[3] with temperatures often matching and even exceeding that ofPhoenix, Arizona in its hottest years; the city's annual high temperature averages at 112 °F (44 °C).[4]
In the summer, the "Delta Breeze", which comes in from theSan Francisco Bay Area, is known for bringing cooler temperatures and higher humidity to the southern parts of the valley. While it brings comparative relief for residents of Sacramento and Roseville, it often results in somewhat muggy conditions, with dew points sometimes reaching above 70 °F (20 °C) and occasionally pushing theheat index above 115 °F (46 °C) on the hottest days. At times the Breeze is gusty with wind speeds up to 30 mph (50 km/h) in the valley and 45 mph (70 km/h) in the windydelta region. This Breeze can also bring morning low clouds at times into the region, but the clouds generally burn off quickly and temperatures stay cool. Summer-like conditions continue into early to mid-September but weather starts to change to cooler, wetter, foggier weather during October which gives trees vibrant autumn foliage.
Winters, also known as the rainy season, are generally mild to cool, foggy and wet. The valley and lower foothills are completely snowless outside of exceptional years where some flurries may occur. The rainy season runs from November to early-April, with some rainfall in September, October, and May. Up north, the temperature averages in the mid-40s °F (mid-to-high single digits °C) and lows reaching to the low-10s °F (-10 to -12 °C), colder in the northern part of the valley and colder still in the foothills and frost can occur almost anywhere. Farther south near Sacramento, temperatures tend to stay between the low-50s and high-60s °F (10-20 °C), with nighttime temperatures dropping to the mid-30s and 40s °F (1-7 °C). Lower-elevation snowfall (in a relative sense) is more consistent in the foothills immediately above Sacramento and Folsom than anywhere else in California;Pollock Pines at 3,980 feet (1,210 m), gets an average of 65 inches (170 cm) of snow every winter, nearly double that ofYosemite Valley and more than triple that ofLucerne, Switzerland.
During the rainy season, the Sacramento Valley is prone to strong thunderstorms andtornadoes, mostly of EF0 or EF1 intensity, especially inColusa County and areas around Corning and Orland. Flooding does occur at times during wetter periods, usually November to March. Snow in the valley is rare, althoughRedding andRed Bluff, being at the north end of the valley, often experience a light dusting or two per year.Chico may get a rain-snow mix every few years, but, on the average, only snows about every 5 years. Farther south in Sacramento, snow rarely occurs. During the autumn and winter months, the entire Central Valley is susceptible to densetule fog that makes driving hazardous, especially at night and especially south of Corning. The fog can last for weeks depending on how weak the wind is. In more recent years, statewidedroughts in California have further strained both the Sacramento Valley's and the San Joaquin Valley'swater security.[1]
| Climate data for Sacramento, California (Sacramento Executive Airport), 1991–2020 normals, extremes 1941–present[a] | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Record high °F (°C) | 76 (24) | 78 (26) | 88 (31) | 95 (35) | 105 (41) | 115 (46) | 114 (46) | 112 (44) | 114 (46) | 104 (40) | 87 (31) | 74 (23) | 115 (46) |
| Mean maximum °F (°C) | 65.2 (18.4) | 71.1 (21.7) | 78.1 (25.6) | 87.4 (30.8) | 95.3 (35.2) | 103.1 (39.5) | 105.3 (40.7) | 104.1 (40.1) | 100.6 (38.1) | 91.8 (33.2) | 76.5 (24.7) | 65.1 (18.4) | 107.0 (41.7) |
| Mean daily maximum °F (°C) | 56.0 (13.3) | 61.3 (16.3) | 66.3 (19.1) | 72.1 (22.3) | 80.3 (26.8) | 87.9 (31.1) | 92.6 (33.7) | 91.9 (33.3) | 88.5 (31.4) | 78.8 (26.0) | 65.0 (18.3) | 56.0 (13.3) | 74.7 (23.7) |
| Daily mean °F (°C) | 47.6 (8.7) | 51.4 (10.8) | 55.4 (13.0) | 59.5 (15.3) | 66.1 (18.9) | 72.2 (22.3) | 75.9 (24.4) | 75.3 (24.1) | 72.5 (22.5) | 64.5 (18.1) | 53.9 (12.2) | 47.3 (8.5) | 61.8 (16.6) |
| Mean daily minimum °F (°C) | 39.2 (4.0) | 41.5 (5.3) | 44.5 (6.9) | 47.0 (8.3) | 52.0 (11.1) | 56.5 (13.6) | 59.2 (15.1) | 58.8 (14.9) | 56.5 (13.6) | 50.3 (10.2) | 42.7 (5.9) | 38.5 (3.6) | 48.9 (9.4) |
| Mean minimum °F (°C) | 29.1 (−1.6) | 31.7 (−0.2) | 35.1 (1.7) | 37.9 (3.3) | 44.1 (6.7) | 49.5 (9.7) | 54.1 (12.3) | 53.8 (12.1) | 49.6 (9.8) | 41.7 (5.4) | 32.7 (0.4) | 28.7 (−1.8) | 26.9 (−2.8) |
| Record low °F (°C) | 20 (−7) | 23 (−5) | 26 (−3) | 31 (−1) | 34 (1) | 41 (5) | 48 (9) | 48 (9) | 42 (6) | 35 (2) | 26 (−3) | 18 (−8) | 18 (−8) |
| Averageprecipitation inches (mm) | 3.66 (93) | 3.49 (89) | 2.68 (68) | 1.26 (32) | 0.75 (19) | 0.23 (5.8) | 0.00 (0.00) | 0.04 (1.0) | 0.09 (2.3) | 0.85 (22) | 1.66 (42) | 3.43 (87) | 18.14 (461) |
| Average precipitation days(≥ 0.01 in) | 10.0 | 9.1 | 9.0 | 5.1 | 3.6 | 1.1 | 0.1 | 0.2 | 0.7 | 3.1 | 6.1 | 9.6 | 57.7 |
| Averagerelative humidity (%) | 83.3 | 76.8 | 71.6 | 64.5 | 58.9 | 55.0 | 53.2 | 55.7 | 57.0 | 63.1 | 75.6 | 82.9 | 66.5 |
| Averagedew point °F (°C) | 39.4 (4.1) | 42.1 (5.6) | 42.8 (6.0) | 43.7 (6.5) | 46.9 (8.3) | 50.4 (10.2) | 53.1 (11.7) | 53.4 (11.9) | 50.9 (10.5) | 47.5 (8.6) | 43.7 (6.5) | 39.2 (4.0) | 46.1 (7.8) |
| Mean monthlysunshine hours | 145.5 | 201.3 | 278.0 | 329.6 | 406.3 | 419.5 | 440.2 | 406.9 | 347.8 | 296.7 | 194.9 | 141.1 | 3,607.8 |
| Percentagepossible sunshine | 48 | 67 | 75 | 83 | 92 | 94 | 98 | 96 | 93 | 86 | 64 | 48 | 81 |
| Source: NOAA (relative humidity, dew point and sun 1961–1990)[6][7][8] | |||||||||||||
| Climate data for Sacramento 5 ESE, California (Sacramento State[9]), 1991–2020 normals, extremes 1877–present | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Record high °F (°C) | 79 (26) | 80 (27) | 90 (32) | 98 (37) | 107 (42) | 112 (44) | 114 (46) | 112 (44) | 116 (47) | 102 (39) | 86 (30) | 72 (22) | 116 (47) |
| Mean maximum °F (°C) | 66.4 (19.1) | 72.5 (22.5) | 80.6 (27.0) | 89.5 (31.9) | 97.1 (36.2) | 104.4 (40.2) | 106.7 (41.5) | 105.5 (40.8) | 102.0 (38.9) | 92.3 (33.5) | 77.3 (25.2) | 65.9 (18.8) | 108.1 (42.3) |
| Mean daily maximum °F (°C) | 56.5 (13.6) | 62.2 (16.8) | 67.8 (19.9) | 73.5 (23.1) | 81.3 (27.4) | 89.0 (31.7) | 94.4 (34.7) | 93.5 (34.2) | 89.3 (31.8) | 78.9 (26.1) | 65.3 (18.5) | 56.4 (13.6) | 75.7 (24.3) |
| Daily mean °F (°C) | 48.8 (9.3) | 52.9 (11.6) | 57.2 (14.0) | 61.4 (16.3) | 67.7 (19.8) | 73.9 (23.3) | 77.9 (25.5) | 77.3 (25.2) | 74.0 (23.3) | 65.9 (18.8) | 55.3 (12.9) | 48.5 (9.2) | 63.4 (17.4) |
| Mean daily minimum °F (°C) | 41.1 (5.1) | 43.7 (6.5) | 46.7 (8.2) | 49.3 (9.6) | 54.0 (12.2) | 58.7 (14.8) | 61.4 (16.3) | 61.0 (16.1) | 58.8 (14.9) | 52.9 (11.6) | 45.3 (7.4) | 40.7 (4.8) | 51.1 (10.6) |
| Mean minimum °F (°C) | 32.5 (0.3) | 35.4 (1.9) | 38.8 (3.8) | 41.6 (5.3) | 47.2 (8.4) | 51.9 (11.1) | 55.9 (13.3) | 55.9 (13.3) | 52.4 (11.3) | 45.1 (7.3) | 36.2 (2.3) | 31.9 (−0.1) | 30.5 (−0.8) |
| Record low °F (°C) | 19 (−7) | 21 (−6) | 29 (−2) | 34 (1) | 37 (3) | 43 (6) | 47 (8) | 48 (9) | 44 (7) | 34 (1) | 27 (−3) | 17 (−8) | 17 (−8) |
| Averageprecipitation inches (mm) | 3.87 (98) | 3.63 (92) | 2.82 (72) | 1.44 (37) | 0.86 (22) | 0.21 (5.3) | 0.00 (0.00) | 0.02 (0.51) | 0.15 (3.8) | 0.93 (24) | 1.78 (45) | 3.49 (89) | 19.20 (488) |
| Average precipitation days(≥ 0.01 in) | 10.8 | 9.6 | 9.2 | 5.3 | 3.7 | 1.2 | 0.1 | 0.2 | 0.8 | 3.1 | 6.8 | 10.1 | 60.9 |
| Source: NOAA[6][10][11], Western Regional Climate Center[12] | |||||||||||||
| Climate data for Chico, California (1981–2010 normals) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Record high °F (°C) | 77 (25) | 82 (28) | 93 (34) | 98 (37) | 108 (42) | 115 (46) | 117 (47) | 116 (47) | 114 (46) | 107 (42) | 91 (33) | 78 (26) | 117 (47) |
| Mean daily maximum °F (°C) | 55.1 (12.8) | 61.1 (16.2) | 66.3 (19.1) | 72.6 (22.6) | 81.3 (27.4) | 88.7 (31.5) | 94.2 (34.6) | 93.7 (34.3) | 89.7 (32.1) | 79.4 (26.3) | 64.8 (18.2) | 55.6 (13.1) | 75.3 (24.1) |
| Mean daily minimum °F (°C) | 35.4 (1.9) | 38.3 (3.5) | 41.5 (5.3) | 45.2 (7.3) | 51.9 (11.1) | 56.7 (13.7) | 60.5 (15.8) | 58.3 (14.6) | 54.6 (12.6) | 46.9 (8.3) | 39.9 (4.4) | 35.3 (1.8) | 47.1 (8.4) |
| Record low °F (°C) | 12 (−11) | 16 (−9) | 23 (−5) | 27 (−3) | 30 (−1) | 38 (3) | 40 (4) | 38 (3) | 35 (2) | 23 (−5) | 20 (−7) | 11 (−12) | 11 (−12) |
| Averageprecipitation inches (mm) | 4.86 (123) | 4.42 (112) | 4.29 (109) | 1.75 (44) | 1.04 (26) | .48 (12) | .02 (0.51) | .08 (2.0) | .42 (11) | 1.42 (36) | 3.28 (83) | 4.61 (117) | 26.67 (677) |
| Source: Western Regional Climate Center[13] | |||||||||||||
| Climate data for Redding, California (1961–1990) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Mean daily maximum °F (°C) | 57.3 (14.1) | 61.3 (16.3) | 62.5 (16.9) | 69.9 (21.1) | 80.5 (26.9) | 90.4 (32.4) | 98.3 (36.8) | 95.7 (35.4) | 89.3 (31.8) | 77.6 (25.3) | 62.1 (16.7) | 54.7 (12.6) | 74.8 (23.8) |
| Daily mean °F (°C) | 45.5 (7.5) | 50.7 (10.4) | 52.5 (11.4) | 58 (14) | 66.4 (19.1) | 76.1 (24.5) | 81.5 (27.5) | 79.5 (26.4) | 74.1 (23.4) | 63.5 (17.5) | 51.8 (11.0) | 45 (7) | 62 (17) |
| Mean daily minimum °F (°C) | 35.7 (2.1) | 40 (4) | 41.7 (5.4) | 46 (8) | 52.3 (11.3) | 61.8 (16.6) | 64.7 (18.2) | 63.1 (17.3) | 58.8 (14.9) | 49.2 (9.6) | 41.4 (5.2) | 35.2 (1.8) | 49.2 (9.6) |
| Averageprecipitation inches (mm) | 6.06 (154) | 4.45 (113) | 4.38 (111) | 2.08 (53) | 1.27 (32) | 0.56 (14) | 0.17 (4.3) | 0.46 (12) | 0.91 (23) | 2.24 (57) | 5.21 (132) | 5.51 (140) | 33.3 (850) |
| Average precipitation days | 13.1 | 8.7 | 12.3 | 7.9 | 7.2 | 4.0 | 0.6 | 0.9 | 2.1 | 4.1 | 6.8 | 10.2 | 77.9 |
| Mean monthlysunshine hours | 226 | 256 | 312 | 351 | 395 | 423 | 451 | 421 | 338 | 314 | 251 | 204 | 3,942 |
| Source:[14] | |||||||||||||
Interstate 5 is the primary route through the Sacramento Valley, traveling north–south roughly along the valley's western edge.Interstate 80 cuts a northeast-to-southwest swath through the southern end of the valley, mostly throughSacramento and Yolo Counties, and ends at theSan Francisco-Oakland Bay Bridge. Several secondary routes connect the two roads, includingInterstate 505 andState Route 113. The Sacramento area has a web of urban freeways.
Other principal routes in the region includeState Route 99, which runs along the valley's eastern edge, roughly parallel to I-5, from Sacramento until its northern terminus inRed Bluff;State Route 20, which traverses the valley from west to east on its route fromState Route 1 inMendocino County to theDonner Pass;State Route 49, named in honor of theCalifornia Gold Rush and running through many old mining towns in the foothills of the valley; andState Route 45, which runs along the course of the Sacramento River roughly ten miles (16 km) east of I-5.
TheUnion Pacific Railroad serves the valley, with its principal north–south line fromOakland, California toPortland, Oregon, viaSacramento,Marysville,Chico, and Redding. This is also the route ofAmtrak'sCoast Starlight passenger train. The Union Pacific also has two east–west lines, throughDonner Pass (the formerCentral Pacific Railroad), and through theFeather River gorge (the formerWestern Pacific Railroad). Amtrak'sCalifornia Zephyr uses the Donner Pass route. TheBNSF Railway has a line fromKlamath Falls, Oregon, to a junction with the Union Pacific Feather River line atKeddie. The BNSF hastrackage rights on both the UP east–west routes. In addition, theCalifornia Northern Railroad operates the formerSouthern Pacific Railroad line on the west side of the valley fromDavis toTehama (near Red Bluff).

