Climate averages 1991–2020
Pasadena (California), United States weather
by month.
See how the year changes. August has the highest average daily maximum; August has the lowest average monthly rainfall.
Pleasant-weather months by our simple rule: FebruaryMarchAprilMayJuneOctoberNovember
Long-term climate patterns, not a forecast for a particular trip.
Across the year Pasadena (California), United States averages a daytime high of 23.9°C and a nighttime low of 11.2°C, with about 389 mm of rain on roughly 37 days. August is the warmest month (average high 31.7°C) and December the coolest (17.6°C). February is the wettest month with 95 mm; August is the driest with under 1 mm.
Months with pleasant weather by a simple rule (average high between 18°C and 29°C, average low of at least 5°C and at most 8 rain days): February, March, April, May, June, October and November. This looks at temperature and rain only, not humidity, wind, sea temperature or crowds.
The annual picture
A year in Pasadena
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Pasadena (California), United States climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 17.8°C6.1°C | 6.1°C | 86 | 5.8 | 10.210 h |
| February | 18.0°C6.4°C | 6.4°C | 95 | 6.7 | 10.911 h |
| March | 19.7°C7.7°C | 7.7°C | 64 | 6.1 | 12.012 h |
| April | 22.1°C9.1°C | 9.1°C | 24 | 3.6 | 13.013 h |
| May | 24.1°C11.6°C | 11.6°C | 12 | 2.3 | 13.914 h |
| June | 27.2°C14.3°C | 14.3°C | 2.3 | 0.5 | 14.414 h |
| July | 30.5°C17.2°C | 17.2°C | 3.1 | 0.6 | 14.214 h |
| August | 31.7°C17.9°C | 17.9°C | 0.9 | 0.2 | 13.413 h |
| September | 30.2°C16.5°C | 16.5°C | 3.9 | 0.9 | 12.412 h |
| October | 26.2°C12.9°C | 12.9°C | 18 | 2.3 | 11.411 h |
| November | 21.8°C9.1°C | 9.1°C | 22 | 3.0 | 10.410 h |
| December | 17.6°C5.8°C | 5.8°C | 58 | 5.2 | 9.910 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
Nearby cities
- Glendale (California), United StatesUnited States · 10 kmHigh 24.3°C · Low 11.6°C · 389 mm rain a year
- El MonteUnited States · 14 kmHigh 25.1°C · Low 12.4°C · 360 mm rain a year
- East Los AngelesUnited States · 14 kmHigh 23.7°C · Low 11.9°C · 341 mm rain a year
- Los AngelesUnited States · 14 kmHigh 24.9°C · Low 12.0°C · 341 mm rain a year
- BurbankUnited States · 16 kmHigh 25.2°C · Low 12.3°C · 389 mm rain a year
- West CovinaUnited States · 21 kmHigh 24.8°C · Low 12.2°C · 360 mm rain a year
- WhittierUnited States · 21 kmHigh 24.1°C · Low 11.8°C · 360 mm rain a year
- DowneyUnited States · 23 kmHigh 23.7°C · Low 12.1°C · 341 mm rain a year
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsWhat do the high and low temperatures mean?
We average the daily maximum and daily minimum for each calendar month over 1991–2020. They are not record extremes, a forecast range or temperatures at a fixed time of day.
How is a rain day counted?
A local calendar day (standard time, UTC-8, no daylight saving) with at least 1 mm of total precipitation counts as one rain day. We count these for each year and month, then average across 30 years. The average does not predict which days will be wet.
Where do the numbers come from?
ERA5-Land (temperature) and ERA5 (precipitation) reanalysis from the Copernicus Climate Change Service, read from the Open-Meteo open-data archive. Temperature comes from the 0.1° model cell at 34.10°, -118.10° (7 km from the city centre), adjusted down by 0.6°C for the difference between the city's elevation (272 m) and the cell's (173 m). Rain comes from the 0.25° cell at 34.25°, -118.25°. Glendale (California), United States and Burbank lie in the same rainfall cell, so their rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells. These are model estimates, not weather-station readings; coast, hills and city streets can differ.
Does this page show sunshine, humidity or sea temperature?
No. The data used here contain air temperature and precipitation only. Daylight hours are calculated from the city's latitude (sunrise to sunset), not measured sunshine.