Pasadena, CA weather in September
Pasadena is hot and dry in September: highs average 90°F and nights drop to about 62°F. Expect about 1 wet day. This is the peak of the warm season in Pasadena.
- Normal high
- 90°F
- Normal low
- 62°F
- Wet days
- 1
- 0.2 in total
- Muggy days
- 1
- dew point 65°F+
How September changes from start to finish
| September 1 | September 30 | |
|---|---|---|
| Normal high | 92°F | 87°F |
| Normal low | 63°F | 59°F |
| Chance of a wet day | 2% | 5% |
| Sunrise / sunset | 6:26 am / 7:19 pm | 6:46 am / 6:38 pm |
| Daylight | 12.9 h | 11.9 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Pacific Time).
A typical September day
- 6 am64°Fdew point 53°F
- 9 am74°Fdew point 54°F
- Noon84°Fdew point 54°F
- 3 pm85°Fdew point 53°F
- 6 pm77°Fdew point 55°F
- 9 pm71°Fdew point 56°F
NOAA hourly normals (local standard time) from Burbank Glendale Pasadena Airport (13 mi away); average wind 5 mph; clear or few clouds in 87% of daytime hours, mostly cloudy or overcast in 11%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F3 of 30
- Hot dayshigh 90°F or more16 of 30
- Muggy daysdaily mean dew point 65°F or more1 of 30
- Wet daysat least 0.01 in of rain or melted snow1 of 30
- Notable rainat least 0.10 in0 of 30
- Freezing nightslow 32°F or below0 of 30
Average days per September, counted from daily records for each year 1991-2020.
Rain in September
Normal precipitation is 0.2 in; a dry September brings about 0.0 in and a wet one about 0.1 in (25th and 75th percentiles). Days with half an inch or more are rare.
How September varies from year to year
- Warmest September, 1991-20202020: average high 96°F
- Coolest September1998: average high 85°F
- Wettest September2015: 1.9 in
- Driest September1992: no measurable precipitation
- Highest reading115°F (September 6, 2020)
- Lowest reading49°F (September 29, 1994)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
September compared with August and October
| August | September | October | |
|---|---|---|---|
| Normal high | 91°F | 90°F | 83°F |
| Normal low | 63°F | 62°F | 56°F |
| Wet days | 0 | 1 | 3 |
| Comfortable days | 0 | 3 | 11 |
| Daylight | 13.4 h | 12.4 h | 11.3 h |
Highs change by -1°F from August and -7°F into October.
Nearby alternatives in September
- Warmer: Palm Springs, CA94 mi · high 102°F · 1 wet day
- Cooler: Los Angeles, CA9 mi · high 83°F · 0 wet days
How Pasadena ranks in September
- Normal high55th warmest of 378 cities; 21st of 60 in California
- Wet days33rd driest of 378
- Comfortable days235th most of 342
What to pack for Pasadena in September
- Light, breathable clothing – highs near 90°F
- Layers – afternoons near 90°F but nights near 62°F
Heating and cooling
September has 2 heating degree days and 324 cooling degree days (base 65°F), 11% of the year's total heating and cooling demand.
Questions
How hot is Pasadena in September?
The normal high is 90°F and the normal low is 62°F. From 1991 to 2020 the hottest September reading was 115°F (September 6, 2020).
Does it rain a lot in Pasadena in September?
About 1 days in September have at least 0.01 in of precipitation, and the normal total is 0.2 in. The wettest September in 1991-2020 was in 2015 (1.9 in); the driest was in 1992, with no measurable precipitation.
Is September a good time to visit Pasadena?
September ranks 11th of 12 months on our comfort score for Pasadena (46 out of 100). It has about 3 comfortable days and about 16 days at 90°F or hotter. The best month is May.
Where the numbers come from
- Temperature, rain and frost dates: Pasadena (USC00046719), 0.0 mi NNW of the city center, 864 ft . NOAA normals and daily records, 1991-2020.
- Snowfall and snow depth: U C L A (USC00049152), 18 mi WSW of the city center, 430 ft (433 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour and cloud cover: Burbank Glendale Pasadena Airport (USW00023152), 13 mi WNW of the city center, 741 ft (122 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Burbank-Glendale-Pasa Arpt (722880-23152), 13 mi WNW of the city center, 731 ft (132 ft lower than the city). Hourly observations, 1991-2020.