Altadena and South Pasadena have remarkably similar climates.
The year at a glance
Averages from 30 years of climate history, 1991-2020
| Altadena | Metric | South Pasadena |
|---|---|---|
| 294 days | Sunny daysclear or partly cloudy skies | 292 days |
| 15 in | Precipitationper year | 13 in |
| 37 days | Wet daysrain or snow per year | 30 days |
| 0 in | Snowfallper year | 0 in |
| 71 days | Hot daysabove 90 °F | 68 days |
| 0 days | Freezing nightsat or below 32 °F | 0 days |
| 56% | Humidityaverage relative | 60% |
| 66 °F | Average temperatureyear round | 66 °F |
Monthly temperatures
Average daily high and low for each month, in °F. The gap between the two lines is what an ordinary day feels like across the year.
Daily highs
Daily lows
View monthly temperatures as a table
| City | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Altadena high | 68 | 69 | 72 | 76 | 78 | 83 | 88 | 91 | 89 | 83 | 75 | 67 |
| South Pasadena high | 68 | 69 | 72 | 75 | 77 | 82 | 87 | 90 | 88 | 82 | 74 | 67 |
| Altadena low | 45 | 46 | 49 | 51 | 55 | 58 | 62 | 64 | 62 | 56 | 49 | 45 |
| South Pasadena low | 46 | 47 | 49 | 52 | 55 | 59 | 63 | 64 | 62 | 57 | 50 | 45 |
Monthly precipitation
Total rain plus melted snow for each month, in inches. Taller bars mean wetter months.
View monthly precipitation as a table
| City | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Altadena | 3.4 | 3.7 | 2.5 | 1.0 | 0.5 | 0.1 | 0.1 | 0.0 | 0.2 | 0.7 | 0.9 | 2.3 |
| South Pasadena | 3.2 | 3.4 | 2.2 | 0.8 | 0.3 | 0.1 | 0.1 | 0.0 | 0.1 | 0.6 | 0.8 | 2.0 |
Monthly sunny days
Days each month with clear or partly cloudy skies, so compare the same month between cities.
View monthly sunny days as a table
| City | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Altadena | 20 | 17 | 21 | 23 | 25 | 28 | 29 | 30 | 29 | 27 | 24 | 22 |
| South Pasadena | 20 | 18 | 21 | 23 | 24 | 27 | 29 | 30 | 28 | 27 | 24 | 21 |
Keep comparing
Nearby cities and popular picks for each side of this matchup. Any two cities can be compared from the home page.
Altadena vs another city
- Altadena vs Pasadena, CA
- Altadena vs La Cañada Flintridge, CA
- Altadena vs San Marino, CA
- Altadena vs East Pasadena, CA
- Altadena vs Sierra Madre, CA
- Altadena vs New York, NY
- Altadena vs Los Angeles, CA
- Altadena vs Chicago, IL
- Altadena vs Houston, TX
- Altadena vs Phoenix, AZ
- Altadena vs Philadelphia, PA
South Pasadena vs another city
- South Pasadena vs Alhambra, CA
- South Pasadena vs San Marino, CA
- South Pasadena vs San Gabriel, CA
- South Pasadena vs Pasadena, CA
- South Pasadena vs Monterey Park, CA
- South Pasadena vs East San Gabriel, CA
- South Pasadena vs New York, NY
- South Pasadena vs Los Angeles, CA
- South Pasadena vs Chicago, IL
- South Pasadena vs Houston, TX
- South Pasadena vs Phoenix, AZ
- South Pasadena vs Philadelphia, PA
About this data
Every figure on this page is a 30 year average computed from daily climate history for 1991-2020, using each city's own coordinates. Wet days count days with measurable precipitation, calibrated against the wet day counts in NOAA's published climate normals. Sunny days count clear plus partly cloudy days, defined as average cloud cover of 63 percent or less and calibrated against NOAA's published sky cover tables. Snowfall figures are model estimates anchored to NOAA station measurements near each city.
Weather data by Open-Meteo.com (CC BY 4.0). Contains modified Copernicus Climate Change Service information (ERA5, ERA5-Land).