Pomona, CA weather in September
In September, Pomona sees highs around 91°F and lows around 64°F: hot and dry. There are about 1 day with rain.
- Normal high
- 91°F
- Normal low
- 64°F
- Wet days
- 1
- 0.2 in total
- Daylight
- 12.4 h
How September changes from start to finish
| September 1 | September 30 | |
|---|---|---|
| Normal high | 95°F | 87°F |
| Normal low | 65°F | 61°F |
| Chance of a wet day | 2% | 5% |
| Sunrise / sunset | 6:24 am / 7:17 pm | 6:44 am / 6:37 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 (36 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 (temperature only: no humidity station nearby)4 of 30
- Hot dayshigh 90°F or more18 of 30
- Wet daysat least 0.01 in of rain or melted snow1 of 30
- Notable rainat least 0.10 in1 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 0.08 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 97°F
- Coolest September1998: average high 84°F
- Wettest September2015: 1.8 in
- Driest September1992: no measurable precipitation
- Highest reading118°F (September 5, 2020)
- Lowest reading51°F (September 27, 2013)
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 | 95°F | 91°F | 83°F |
| Normal low | 65°F | 64°F | 57°F |
| Wet days | 0 | 1 | 3 |
| Comfortable days | 1 | 4 | 13 |
| Daylight | 13.4 h | 12.4 h | 11.3 h |
Highs change by -4°F from August and -8°F into October.
Nearby alternatives in September
- Warmer: Palm Springs, CA71 mi · high 102°F · 1 wet day
- Cooler: West Covina, CA11 mi · high 83°F · 1 wet day
How Pomona ranks in September
- Normal high31st warmest of 378 cities; 13th of 60 in California
- Wet days48th driest of 378
What to pack for Pomona in September
- Light, breathable clothing – highs near 91°F
- Layers – afternoons near 91°F but nights near 64°F
Heating and cooling
September has 1 heating degree days and 378 cooling degree days (base 65°F), 12% of the year's total heating and cooling demand.
Questions
How hot is Pomona in September?
The normal high is 91°F and the normal low is 64°F. From 1991 to 2020 the hottest September reading was 118°F (September 5, 2020).
Does it rain a lot in Pomona 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 (1.8 in); the driest was in 1992, with no measurable precipitation.
Is September a good time to visit Pomona?
September ranks 10th of 12 months on our comfort score for Pomona (47 out of 100). It has about 4 comfortable days (judged by temperature only) and about 18 days at 90°F or hotter. The best months are March, April and May.
Where the numbers come from
- Temperature: Ontario Intl Airport (USW00003102), 8.7 mi E of the city center, 949 ft (100 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Rain: San Gabriel Canyon PH (USC00047776), 11 mi NW of the city center, 744 ft (105 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Snowfall and snow depth: Covina City Yard Fc387b (USC00042090), 7.7 mi WNW of the city center, 607 ft (242 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Frost dates: Pomona/Fairplex (USC00047050), 2.0 mi NNW of the city center, 999 ft (150 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour and cloud cover: Burbank Glendale Pasadena Airport (USW00023152), 36 mi WNW of the city center, 741 ft (108 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Not available for this location: daily humidity and wind (no station close enough or similar enough in elevation).