The year at a glance
Averages from 30 years of climate history, 1991-2020
| Altadena | Metric | Chicago |
|---|---|---|
| 294 days | Sunny daysclear or partly cloudy skies | 180 days |
| 15 in | Precipitationper year | 39 in |
| 37 days | Wet daysrain or snow per year | 132 days |
| 0 in | Snowfallper year | 37 in |
| 71 days | Hot daysabove 90 °F | 16 days |
| 0 days | Freezing nightsat or below 32 °F | 102 days |
| 56% | Humidityaverage relative | 71% |
| 66 °F | Average temperatureyear round | 52 °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 |
| Chicago high | 32 | 36 | 46 | 57 | 68 | 78 | 83 | 81 | 75 | 62 | 49 | 37 |
| Altadena low | 45 | 46 | 49 | 51 | 55 | 58 | 62 | 64 | 62 | 56 | 49 | 45 |
| Chicago low | 20 | 23 | 31 | 41 | 51 | 61 | 67 | 67 | 60 | 47 | 36 | 25 |
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 |
| Chicago | 2.4 | 2.1 | 2.8 | 4.5 | 4.4 | 4.0 | 3.6 | 3.8 | 3.0 | 3.3 | 2.8 | 2.4 |
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 |
| Chicago | 10 | 11 | 14 | 13 | 15 | 16 | 20 | 20 | 20 | 16 | 14 | 11 |
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 South Pasadena, CA
- Altadena vs New York, NY
- Altadena vs Los Angeles, CA
- Altadena vs Houston, TX
- Altadena vs Phoenix, AZ
- Altadena vs Philadelphia, PA
Chicago vs another city
- Chicago vs Cicero, IL
- Chicago vs Stickney, IL
- Chicago vs Berwyn, IL
- Chicago vs Oak Park, IL
- Chicago vs Riverside, IL
- Chicago vs Forest Park, IL
- Chicago vs New York, NY
- Chicago vs Los Angeles, CA
- Chicago vs Houston, TX
- Chicago vs Phoenix, AZ
- Chicago vs Philadelphia, PA
- Chicago vs San Antonio, TX
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).