Pasadena, California Weather
Ceanothus blooms again. Day 93 of summer. Read this microseason across nine climate regions →
Pasadena weather forecast — hour by hour, 7-day outlook, NOAA radar
Conditions updated 12:20 AM PDT · Open-Meteo
- TodaySep 21Clear later——79°61°—
- TuesdaySep 22Overcast——80°58°+1°
- WednesdaySep 23Clear——88°71°+8°
- ThursdaySep 24Clear——87°72°-1°
- FridaySep 25Overcast——91°73°+4°
- SaturdaySep 26Overcast——91°77°0°
- SundaySep 27Overcast——92°78°+1°
Air quality now AQI 67 · Moderate
AQI 67 (Moderate), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 16.1 µg/m³ (AQI 64) with a 0.86 fine-to-coarse ratio and 2 mph wind — combustion smoke trapped in stagnant air, not road dust.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
PM × Wind × Precip
PM2.5 at 16.1 µg/m³ (AQI 64) with a 0.86 fine-to-coarse ratio and 2 mph wind — combustion smoke trapped in stagnant air, not road dust.
- PM2.5/PM10
- 0.86
- Wind
- calm
- Recent rain
- 0h in last 6h
- Pattern
- stagnant smoke
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).
September dries up ditches or breaks down bridges.
- Moonrise
- 4:12 PM
- Moonset
- 1:36 AM
- In sign
- ♑︎ Capricorn
Ceanothus blooms again
Read this microseason across nine climate regions →
All 72 microseasons on the year wheel →
Pasadena at a glance
- Today vs. normal: Today averages 70°F (high 79°F, low 61°F), 2°F below the 72°F normal for Sep 21
- Last frost: None in most years — 32°F in 13% of 1991–2020 years (NOAA station 1 km away)
- Microseason: Sep 21–25
- Planting calendar: September — plant lettuce, peas, spinach, radishes, beans, squash; harvest lettuce, peas, spinach, radishes, tomatoes, peppers, beans, summer squash, winter squash
15-Day Forecast — Pasadena
- Mon78°59°2%
- Tue80°58°0%
- Wed88°71°0%
- Thu87°72°1%
- Fri91°73°1%
- Sat91°77°0%
- Sun92°78°2%
- Mon97°80°4%
- Tue97°85°12%
- Wed88°75°12%
- Thu75°68°3%
- Fri88°71°6%
- Sat91°79°7%
- Sun96°80°5%
- Mon86°76°3%
Forecast data from Open-Meteo (CC BY 4.0).
Live wind & temperature near Pasadena
Interactive wind and temperature map centered on Pasadena — it loads in your browser. Open the full weather map.
Right now in the garden
Year-round growing
As of September 21, sowing here runs through the year. Freezes are uncommon, so there is no frost date to plan around; heat and rainfall set the calendar instead. This city's planting calendar for September: plant lettuce, peas, spinach, radishes, beans, and squash; harvest lettuce, peas, spinach, radishes, tomatoes, peppers, beans, summer squash, and winter squash.
Sun & seasons in Pasadena
Pasadena sits in Los Angeles County, where the year’s longest day runs 14h 26m of daylight and its shortest just 9h 52m — a swing of +4h 34m between the June and December solstices. Clocks spring forward on Sunday, March 8, 2026 and fall back on Sunday, November 1, 2026.
Los Angeles, the state’s largest city, lies about 16 miles to the WSW. The nearest town Pasadena tracks is Glendale, roughly 6 miles to the WNW.
Air quality in Pasadena
Air quality in Pasadena’s county has trended cleaner since 2020; its cleanest year on record was 2023 (median AQI 67). See the full air-quality history for Pasadena.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | lettuce, peas, spinach, radishes | lettuce, peas, spinach, radishes |
| February | lettuce, peas, spinach, radishes | lettuce, peas, spinach, radishes |
| March | lettuce, peas, spinach, radishes | lettuce, peas, spinach, radishes |
| April | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, spinach, radishes |
| May | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, spinach, radishes, beans, summer squash |
| June | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, summer squash |
| July | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, summer squash, winter squash |
| August | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, summer squash, winter squash |
| September | lettuce, peas, spinach, radishes, beans, squash | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, summer squash, winter squash |
| October | lettuce, peas, spinach, radishes | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, summer squash, winter squash |
| November | lettuce, peas, spinach, radishes | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, summer squash, winter squash |
| December | lettuce, peas, spinach, radishes | lettuce, peas, spinach, radishes |
A year in weather
Pasadena's warmest month is August (~76°F mean) and its coldest is December (~55°F). Rainfall peaks in February (4.5 inches) and bottoms out in August (0.0 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 56° | 3.6″ | 5 |
| February | 56° | 4.5″ | 5 |
| March | 59° | 2.8″ | 4 |
| April | 62° | 0.9″ | 2 |
| May | 65° | 0.4″ | 1 |
| June | 69° | 0.1″ | 0 |
| July | 74° | 0.0″ | 0 |
| August | 76° | 0.0″ | 0 |
| September | 74° | 0.1″ | 0 |
| October | 68° | 0.7″ | 1 |
| November | 60° | 0.8″ | 2 |
| December | 55° | 2.5″ | 4 |
Regional context
Similar climates Altadena, CA, San Pasqual, CA, San Marino, CA
Pasadena's climate, from NOAA NCEI 1991-2020 station normals, pairs 56°F Januarys with 74°F Julys — an 18°F swing. About 16.5 inches of precipitation falls over roughly 24 days a year.
Cool-season fronts carry Pasadena's rain: February logs 4.5 inches on 5.1 days, against August's 0.0 inches on 0.1 — winter does the heavy lifting in Pasadena. That groups Pasadena with places like Altadena, CA, San Pasqual, CA and San Marino, CA on the same cool-season storm track.
Pasadena rarely sees a hard freeze — its coldest month sits near 55°F — so planting spans most of the calendar. Heat peaks in August around 76°F, which confines cool-season crops to the shoulders of summer. Pasadena beds by a wall stay warmer at night.
Similar climates: Altadena, CA, San Pasqual, CA, San Marino, CA, South Pasadena, CA, East Pasadena, CA.
Frequently asked
- When does it freeze in Pasadena?
- Pasadena freezes in fewer than half of years — 13% of 1991–2020 years at the nearest NOAA station — so Pasadena has no typical frost date.
- What is the rainy season in Pasadena?
- February is the wettest month in Pasadena, about 4.5 inches on average; the year totals roughly 17 inches.
- What is the warmest month in Pasadena?
- On average August tops the year in Pasadena at about 76°F.
- What is the coldest month in Pasadena?
- The coldest stretch in Pasadena falls in December, around 55°F on average.
- When can I start a vegetable garden in Pasadena?
- Start whenever suits in Pasadena — freezes are too rare for a frost date — and save lettuce and peas for Pasadena's coolest stretch, near 55°F.
- How many rainy days does Pasadena get?
- Pasadena averages about 24 days with measurable rain or snow each year.
- What hardiness zone is Pasadena?
- With December around 55°F, Pasadena's zone reflects that minimum — the USDA ZIP map confirms Pasadena's band.
- What is the 10-day forecast for Pasadena?
- Pasadena's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
- Will it rain this week in Pasadena?
- See this week's day-by-day rain chances for Pasadena in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Pasadena?
- Current conditions for Pasadena and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Pasadena forecast updated?
- The Pasadena forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Pasadena?
- Today's sunrise and sunset times for Pasadena are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
- How accurate is the weather forecast for Pasadena?
- The next few days in Pasadena's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Pasadena sits at 34.2°N; its climate zone is hot-summer Mediterranean (Köppen approximation).
ZIP codes in Pasadena
- 91101
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- 91104
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- 91106
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