Yosemite Valley, CA weather in September
September in Yosemite Valley: warm and dry. Highs 83°F, lows 51°F, about 2 days with rain.
- Normal high
- 83°F
- Normal low
- 51°F
- Wet days
- 2
- 0.4 in total
- Daylight
- 12.4 h
How September changes from start to finish
| September 1 | September 30 | |
|---|---|---|
| Normal high | 87°F | 78°F |
| Normal low | 55°F | 47°F |
| Chance of a wet day | 5% | 7% |
| Sunrise / sunset | 6:28 am / 7:28 pm | 6:53 am / 6:43 pm |
| Daylight | 13.0 h | 11.8 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Pacific Time).
What kind of days to expect
- Comfortable dayshigh 65-80°F (temperature only: no humidity station nearby)8 of 30
- Hot dayshigh 90°F or more6 of 30
- Wet daysat least 0.01 in of rain or melted snow2 of 30
- Notable rainat least 0.10 in1 of 30
- Freezing nightslow 32°F or below0 of 30
- Snow on the groundsnow depth 1 in or more0 of 30
Average days per September, counted from daily records for each year 1991-2020.
Rain in September
Normal precipitation is 0.4 in; a dry September brings about 0.05 in and a wet one about 0.4 in (25th and 75th percentiles). Days with half an inch or more are rare.
How September varies from year to year
- Warmest September, 1991-20202012: average high 87°F
- Coolest September1998: average high 78°F
- Wettest September2011: 3.4 in
- Driest September1993: no measurable precipitation
- Highest reading99°F (September 5, 2020)
- Lowest reading32°F (September 20, 2007)
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 | 89°F | 83°F | 71°F |
| Normal low | 57°F | 51°F | 41°F |
| Wet days | 1 | 2 | 3 |
| Comfortable days | 2 | 8 | 18 |
| Daylight | 13.6 h | 12.4 h | 11.2 h |
Highs change by -6°F from August and -12°F into October.
Nearby alternatives in September
- Warmer: Fresno, CA70 mi · high 91°F · 1 wet day
- Cooler: Mammoth Lakes, CA34 mi · high 71°F · 2 wet days
How Yosemite Valley ranks in September
- Normal high165th warmest of 378 cities; 41st of 60 in California
- Wet days60th driest of 378
What to pack for Yosemite Valley in September
- Layers – afternoons near 83°F but nights near 51°F
Heating and cooling
September has 53 heating degree days and 118 cooling degree days (base 65°F), 3% of the year's total heating and cooling demand.
Questions
How hot is Yosemite Valley in September?
The normal high is 83°F and the normal low is 51°F. From 1991 to 2020 the hottest September reading was 99°F (most recently on September 5, 2020).
Does it rain a lot in Yosemite Valley in September?
About 2 days in September have at least 0.01 in of precipitation, and the normal total is 0.4 in. The wettest September in 1991-2020 was in 2011 (3.4 in); the driest was in 1993, with no measurable precipitation.
Is September a good time to visit Yosemite Valley?
September ranks 5th of 12 months on our comfort score for Yosemite Valley (59 out of 100). It has about 8 comfortable days (judged by temperature only) and about 6 days at 90°F or hotter. The best month is May.
Where the numbers come from
- Temperature, rain and frost dates: Yosemite Park Hq (USC00049855), 0.8 mi NW of the city center, 4,018 ft (52 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Snowfall and snow depth: Hetch Hetchy (USC00043939), 19 mi NW of the city center, 3,870 ft (96 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Not available for this location: humidity and wind by hour, cloud cover and daily humidity and wind (no station close enough or similar enough in elevation).