Norwalk, California climate: NOAA's gridded normals for the city, beside the nearest station records
NOAA's gridded 1991-2020 normals put Norwalk's center at January lows of 47°F and July highs of 84°F, a yearly mean of 65.7°F and 12.2 inches of precipitation. No NOAA station keeps a record under the city's name. The nearest station record, Fullerton (6 miles E, 96 ft), has January lows of 46°F and July highs of 84°F.
98,230 people (Census Bureau 2024). Distances and directions are from the city's center.
- Jan 70° 47°
- Feb 69° 48°
- Mar 71° 50°
- Apr 74° 53°
- May 76° 57°
- Jun 79° 60°
- Jul 84° 64°
- Aug 86° 64°
- Sep 85° 62°
- Oct 80° 58°
- Nov 75° 51°
- Dec 69° 46°
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 Norwalk's center.
What is each month like in Norwalk?
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. | Fullerton high | Fullerton low |
|---|---|---|---|---|---|---|
| January | 70°F | 47°F | 58.1°F | 2.89 | 69°F | 46°F |
| February | 69°F | 48°F | 58.6°F | 3.20 | 69°F | 48°F |
| March | 71°F | 50°F | 60.7°F | 1.80 | 71°F | 52°F |
| April | 74°F | 53°F | 63.3°F | 0.64 | 74°F | 54°F |
| May | 76°F | 57°F | 66.1°F | 0.23 | 76°F | 58°F |
| June | 79°F | 60°F | 69.6°F | 0.05 | 79°F | 63°F |
| July | 84°F | 64°F | 73.8°F | 0.02 | 84°F | 66°F |
| August | 86°F | 64°F | 75.0°F | 0.01 | 87°F | 66°F |
| September | 85°F | 62°F | 73.7°F | 0.08 | 85°F | 65°F |
| October | 80°F | 58°F | 69.0°F | 0.43 | 80°F | 58°F |
| November | 75°F | 51°F | 62.7°F | 0.81 | 74°F | 51°F |
| December | 69°F | 46°F | 57.3°F | 1.98 | 68°F | 46°F |
In metric: a yearly mean of 18.7°C, January lows of 8°C, July highs of 29°C and 309 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 Norwalk 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 |
|---|---|---|---|---|---|---|---|---|
| FullertonFullerton Municipal Airport | 6 mi E | 96 ft | 66.2°F | 46°F | 84°F | 11.9 | – | – |
| Long BeachLong Beach Daugherty Field | 8 mi SW | 31 ft | 64.9°F | 47°F | 81°F | 12.0 | – | – |
| San GabrielSan Gabriel Fire Dept | 12 mi N | 363 ft | 66.0°F | 46°F | 86°F | 15.7 | 0 | January 4 |
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 Norwalk?
NOAA's grid gives no snow, frost dates or records, so these come from the nearest station record, Fullerton (6 miles E, 96 ft). NOAA publishes no snowfall normal for it; the nearest record that has one, San Gabriel (12 miles N), gets 0 inches a year. Frost is rare there: NOAA gives no median frost date. Its record high is 116°F (2018) and its record low 28°F (2007) (kept since 1998).
The USDA's 2023 Plant Hardiness Zone Map puts Norwalk in zone 10b (ZIP code 90650).
Over a year 87% of the sunlight that would reach the ground under clear skies gets through the clouds in the area (5.4 kWh per square metre a day, NASA POWER 2001-2020); August is the sunniest month (92%) and February the cloudiest (83%).
Fullerton'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 Norwalk; the nearest record's month pages have them.
Source: NOAA NCEI 1991-2020 normals, station USW00003166; 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 Norwalk, ZIP code by ZIP code?
One ZIP code area lies wholly or partly in Norwalk. Each row also names the nearest station record and its frost dates.
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.