Simi Valley, California climate: NOAA's gridded normals for the city, beside the nearest station records
NOAA's gridded 1991-2020 normals put Simi Valley's center at January lows of 44°F and July highs of 89°F, a yearly mean of 64.0°F and 16.5 inches of precipitation. No NOAA station keeps a record under the city's name. The nearest station record, Woodland Hills Pierce College (12 miles SE, 790 ft), has January lows of 43°F and July highs of 95°F.
125,778 people (Census Bureau 2024). Distances and directions are from the city's center.
- Jan 67° 44°
- Feb 67° 43°
- Mar 70° 46°
- Apr 74° 48°
- May 77° 52°
- Jun 83° 56°
- Jul 89° 60°
- Aug 91° 60°
- Sep 88° 58°
- Oct 80° 53°
- Nov 73° 47°
- Dec 66° 42°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
The months above are NOAA's gridded normals at Simi Valley's center.
What is each month like in Simi Valley?
NOAA's grid estimates the normals every 5 km or so from the stations around each point, terrain included. It smooths between stations, so night lows at the heart of a large city can run warmer than the grid shows: at five big-city airports we compared, the grid's highs were within about 1°F of the station and its lows 1-6°F cooler. The nearest record's high and low are beside each month.
| Month | High | Low | Mean | Precip. | Woodland Hills Pierce College high | Woodland Hills Pierce College low |
|---|---|---|---|---|---|---|
| January | 67°F | 44°F | 55.2°F | 3.70 | 70°F | 43°F |
| February | 67°F | 43°F | 55.2°F | 4.27 | 70°F | 44°F |
| March | 70°F | 46°F | 57.9°F | 2.68 | 74°F | 46°F |
| April | 74°F | 48°F | 60.6°F | 0.87 | 78°F | 48°F |
| May | 77°F | 52°F | 64.5°F | 0.34 | 82°F | 53°F |
| June | 83°F | 56°F | 69.5°F | 0.05 | 89°F | 57°F |
| July | 89°F | 60°F | 74.7°F | 0.01 | 95°F | 61°F |
| August | 91°F | 60°F | 75.7°F | 0.01 | 97°F | 61°F |
| September | 88°F | 58°F | 73.3°F | 0.09 | 94°F | 59°F |
| October | 80°F | 53°F | 66.9°F | 0.57 | 85°F | 53°F |
| November | 73°F | 47°F | 60.0°F | 1.06 | 76°F | 46°F |
| December | 66°F | 42°F | 54.2°F | 2.86 | 69°F | 42°F |
In metric: a yearly mean of 17.8°C, January lows of 6°C, July highs of 32°C and 419 mm of precipitation a year.
Source: NOAA NCEI U.S. Monthly Gridded Climate Normals 1991-2020 (nClimGrid, accession 0245564); NOAA NCEI 1991-2020 station normals. The grid cell holding the city's Census center point.
What do the station records around Simi Valley say?
Each row is a NOAA station's own 1991-2020 normals, with the snow and frost dates the grid does not give. A record downhill or nearer the coast than the city can run warmer, one uphill cooler: compare the elevations.
| Record | Where | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Woodland Hills Pierce College | 12 mi SE | 790 ft | 66.3°F | 43°F | 95°F | 16.4 | 0 | January 24 |
| Stevenson RanchNewhall (5 mi NW) | 12 mi NE | 1,765 ft | 65.5°F | 47°F | 94°F | 16.8 | 0 | January 8 |
| Northridge Cal State | 13 mi E | 904 ft | 66.2°F | 47°F | 90°F | 14.6 | 0 | January 2 |
Source: NOAA NCEI 1991-2020 U.S. Climate Normals; place center and population: Census Bureau 2024. Last frost: the median last spring date of 32°F.
How much snow, how late a frost, what zone and how much sun in Simi Valley?
NOAA's grid gives no snow, frost dates or records, so these come from the nearest station record, Woodland Hills Pierce College (12 miles SE, 790 ft). It gets 0 inches of snow in a normal year. The last spring frost (32°F) comes after January 24 in half of years and the first autumn frost before December 15. Its record high is 120°F (2020) and its record low 18°F (1989) (kept since 1949).
The USDA's 2023 Plant Hardiness Zone Map puts Simi Valley in zone 10a across its 2 ZIP code areas.
Over a year 90% of the sunlight that would reach the ground under clear skies gets through the clouds in the area (5.7 kWh per square metre a day, NASA POWER 2001-2020); August is the sunniest month (97%) and February the cloudiest (82%).
Woodland Hills Pierce College's page has its months, frost probabilities, records by month and recent years. NOAA's grid has monthly figures only, so there are no day-by-day month pages for Simi Valley; the nearest record's month pages have them.
Source: NOAA NCEI 1991-2020 normals, station USC00049785; records: ACIS; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; sunshine: NASA POWER.
How does the climate vary across Simi Valley, ZIP code by ZIP code?
2 ZIP code areas lie wholly or partly in Simi Valley. On NOAA's grid 93063 is the warmest (64.4°F a year) and 93065 the coolest (63.9°F), a spread of 0.5°F. Each row also names the nearest station record and its frost dates.
| ZIP code | Zone | Year | Jan low | Jul high | Precip. | Nearest record | Last frost | First frost |
|---|---|---|---|---|---|---|---|---|
| 93063 | 10a | 64.4°F | 45°F | 91°F | 18.1 | Stevenson Ranch (8 mi) | January 8 | January 1 |
| 93065 | 10a | 63.9°F | 44°F | 89°F | 16.8 | Woodland Hills Pierce College (13 mi) | January 24 | December 15 |
Source: Census Bureau 2020 ZCTA-to-place relationship file and ZCTA centers; NOAA NCEI gridded and station normals, 1991-2020. A ZIP area counts when at least a tenth of its land (and 0.5 km²) is in the city; its figures are the grid cell at its center; frost dates are the nearest record's medians of 32°F.