Palo Alto weather in September: Palo Alto, California: normal highs, lows, rain and records for September
Palo Alto in September has a normal high of 80°F and a normal low of 53°F, a daily mean of 66°F, falling from 80°F on the 1st to 78°F by the 30th. Measurable precipitation falls on 1 days in a normal September, 0.07 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 26°C and low of 12°C, 2 mm of precipitation in September.
- NOAA stationPalo Alto
- Station IDUSC00046646
- Location37.44°N 122.14°W
- Elevation25 ft (8 m)
- From the center3 miles
- Population67,658
- Jan 58° 39°
- Feb 61° 41°
- Mar 66° 44°
- Apr 70° 45°
- May 73° 50°
- Jun 79° 53°
- Jul 79° 56°
- Aug 79° 55°
- Sep 80° 53°
- Oct 74° 48°
- Nov 64° 43°
- Dec 58° 39°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Palo Alto in September?
The normal high is 80°F and the normal low 53°F, for a daily mean of 66.3°F. September is 0.7°F cooler than August and 5.1°F warmer than October. September is the 3rd warmest month of the year in Palo Alto and the 10th wettest. Across the month the normal high falls 2°F, from 80°F on September 1 to 78°F on September 30. From one year to the next September's mean temperature typically moves about 2.0°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 64°F and 68°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 4%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 80°F | 54°F | 1% | 1% |
| September 8 | 80°F | 54°F | 1% | 1% |
| September 15 | 80°F | 53°F | 2% | 1% |
| September 22 | 79°F | 52°F | 3% | 2% |
| September 30 | 78°F | 51°F | 4% | 2% |
Every day of September: normal high, low and chance of precipitation (warmest afternoon September 8, coldest night September 30)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| September 1 | 80°F | 54°F | 1% | 1% | 13 h |
| September 2 | 80°F | 54°F | 1% | 1% | 13 h |
| September 3 | 80°F | 54°F | 1% | 1% | 13 h |
| September 4 | 80°F | 54°F | 1% | 1% | 12 h 50 min |
| September 5 | 80°F | 54°F | 1% | 1% | 12 h 50 min |
| September 6 | 80°F | 54°F | 1% | 1% | 12 h 50 min |
| September 7 | 80°F | 54°F | 1% | 1% | 12 h 50 min |
| September 8 | 80°F | 54°F | 1% | 1% | 12 h 50 min |
| September 9 | 80°F | 54°F | 2% | 1% | 12 h 40 min |
| September 10 | 80°F | 54°F | 2% | 1% | 12 h 40 min |
| September 11 | 80°F | 54°F | 2% | 1% | 12 h 40 min |
| September 12 | 80°F | 54°F | 2% | 1% | 12 h 40 min |
| September 13 | 80°F | 53°F | 2% | 1% | 12 h 30 min |
| September 14 | 80°F | 53°F | 2% | 1% | 12 h 30 min |
| September 15 | 80°F | 53°F | 2% | 1% | 12 h 30 min |
| September 16 | 80°F | 53°F | 2% | 1% | 12 h 30 min |
| September 17 | 80°F | 53°F | 2% | 1% | 12 h 20 min |
| September 18 | 80°F | 53°F | 2% | 1% | 12 h 20 min |
| September 19 | 80°F | 53°F | 3% | 1% | 12 h 20 min |
| September 20 | 80°F | 53°F | 3% | 1% | 12 h 20 min |
| September 21 | 80°F | 53°F | 3% | 1% | 12 h 10 min |
| September 22 | 79°F | 52°F | 3% | 2% | 12 h 10 min |
| September 23 | 79°F | 52°F | 3% | 2% | 12 h 10 min |
| September 24 | 79°F | 52°F | 3% | 2% | 12 h 10 min |
| September 25 | 79°F | 52°F | 3% | 2% | 12 h 10 min |
| September 26 | 79°F | 52°F | 3% | 2% | 12 h |
| September 27 | 79°F | 52°F | 4% | 2% | 12 h |
| September 28 | 79°F | 52°F | 4% | 2% | 12 h |
| September 29 | 78°F | 51°F | 4% | 2% | 12 h |
| September 30 | 78°F | 51°F | 4% | 2% | 11 h 50 min |
- Normal high
- 80°FSeptember average
- Normal low
- 53°FSeptember average
- Precipitation
- 0.07 inmonth total
- Days with precipitation
- 10.01 inch or more
- Days at 90°F or more
- 4
- Daylight
- 13 h to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 28
- Days at 80°F or more
- 13
- Sunshine
- 82%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00046646; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Palo Alto in September?
On a given September day the chance of 0.01 inch or more is 2% on average, highest around September 30 (4%). In all, 0.07 in falls on 1 days of a normal September.
In a normal September in Palo Alto, 4 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00046646.
What are the records for September in Palo Alto?
The warmest September temperature on this station's record (since 1953) is 105°F, on September 15, 1971; the coldest is 37°F, on September 23, 2010. The wettest September brought 2.31 in (1959).
Source: records: ACIS, station USC00046646. Records and recent months use complete months only.
How does September in Palo Alto compare across California?
Across the 219 places PlainClimate covers in California, September normal highs run from 64°F in Eureka to 104°F in Brawley; Palo Alto's is 80°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- Palo Alto in August79°F by day, 55°F at night
- Palo Alto in October74°F by day, 48°F at night
- Palo Alto through the yearEvery month, frost dates, records and recent years
- California in SeptemberThe statewide normal and the warmest and coolest places
- Brawley: California's warmest Septembernormal high 104°F