September could be a good time to visit San Jose, as the weather is generally fine. The average high temperature is around +75°F, and there are typically 0 sunny days in September. However, expect about 30 rainy days, and total monthly rainfall of approximately 676 mm. The weather is changeable so pack for every eventuality. Search flightsin one click on Avionero.
Average weather
☀️
+75°F
Avg. max. temperature
+57°F
Min.
+84°F
Max.
676 mm
Total precipitation
85%
Avg. humidity
1 m/s
Avg. wind
0 ☀️
Sunny Days
0 ⛅️
Cloudy
30 🌦
Rainy
Our opinion: San Jose has OK weather in September.
Average temperature in San Jose in September
Here are the expected maximum, average and minimum temperatures in San Jose for September based on the historical data.
Last Year
Historical Data
The expected average maximum temperature in September is +77°F with a maximum of +81°F and a minimum of +61°F.
The average maximum temperature goes down 9% by the end of the month, compared with the beginning of the month, from +79°F to +77°F.
Is San Jose warm or cold in September?
San Jose is typically warm in September.
Maximum temperatures go up compared to the previous month from +75°F to +75°F. The minimum temperature also goes down from +64°F to +63°F.
It’s generally warm, but pack a long-sleeve shirt for evenings.
Take a look at how September is compared to other months in San Jose:
Climate in San Jose in September
San Jose weather looks like this, on average, in September and the surrounding months.
August
September
October
Avg. temperature
+75°F
+75°F
+75°F
Min. temperature
+59°F
+57°F
+57°F
Max. temperature
+84°F
+84°F
+84°F
Rainfall
761 mm
676 mm
685 mm
Wind
2 m/s
1 m/s
2 m/s
Humidity
81%
85%
85%
Air pressure
1014 HPa
1013 HPa
1013 HPa
Sunny days
0
0
0
Cloudy days
0
0
0
Rainy days
31
30
31
Snowy days
0
0
0
September weather is still as ok as in August.The temperature levels stay the same in the area of +75°F for average maximum temperature during the day.As September arrives, the amount of rainfall goes down. On average, the rainfall volume decreases from 761 mm to 676 mm.Humidity rises from 81% to 85%.Winds are calmer in comparison to August, going down from 2 m/s to 1 m/s on average.The amount of sunny days stay about the same, averaging 0 sunny days during the month.
October brings much the same weather, it remains ok.
Wind speed in San Jose in September based on historical data.
Last Year
Historical Data
The average wind speed is 2 m/s getting up to 3 m/s which is a light breeze; barely moving the tree leaves.
The average wind speed in San Jose is gradually increasing during September, going from 2 m/s to 2 m/s over the course of the month.
Rain
Amount of rainfall in mm during September in San Jose based on historical data.
Last Year
Historical Data
A chance of rain on a typical day in September stands at 100%, leading to total precipitation of around 727 mm. The maximum amount of rainfall per day is around 102 mm, which is considered heavy rain.September is a pretty wet month with over 30 rainy days, so don’t forget to pack an umbrella, raincoat, and a pair of wellies.
Here’s how September is compared with other months in the amount of precipitation, total mm:
San Jose wettest month is August, where a typical day has a 100% chance of precipitation and 761 mm of rainfall per day. February, on the other hand, is the driest month with a mere 38% chance of precipitation and 86 mm of rainfall per day.
How was the weather last September in San Jose?
This is the weather in San Jose in September 2023:
1 September
🌧️
+78°F
2 September
🌧️
+77°F
3 September
🌧️
+73°F
4 September
🌧️
+78°F
5 September
☁️
+74°F
6 September
☀️
+79°F
7 September
🌧️
+79°F
8 September
☁️
+78°F
9 September
🌧️
+77°F
10 September
🌧️
+77°F
11 September
🌫️
+80°F
12 September
🌧️
+77°F
13 September
🌫️
+74°F
14 September
🌧️
+78°F
15 September
🌧️
+76°F
16 September
🌧️
+79°F
17 September
🌧️
+76°F
18 September
🌧️
+74°F
19 September
☁️
+75°F
20 September
🌧️
+76°F
21 September
🌫️
+77°F
22 September
🌫️
+78°F
23 September
🌧️
+78°F
24 September
🌧️
+80°F
25 September
🌧️
+76°F
26 September
🌧️
+74°F
27 September
🌧️
+78°F
28 September
☁️
+78°F
29 September
☀️
+78°F
30 September
🌧️
+76°F
In September 2023 San Jose had 2 sunny days, 4 cloudy days, and 20 rainy days. The average maximum temperature was +77°F, with an absolute maximum of +81°F and a minimum of +73°F. The average humidity was 86%, with a maximum of 97% and a minimum of 48%. The average wind speed was 2 m/s, with a maximum of 7 m/s and a minimum of 0 m/s.
Are you planning a trip in September?
Climate Change Over the Years
This is how San Jose climate has changed over the last 43 years.
The climate in San Jose in September has not changed that much over the last 43 years.
The average temperature was the lowest in 1999 (+78°F) and the highest in 2009 (+83°F). The driest year was 2006 with only 550 mm of rainfall, and the wettest year was 2020 with 1230 mm.
FAQ
Frequently asked questions about the weather in San Jose in September:
Is September a good time to visit San Jose?
It’s always a good time to visit San Jose, but the weather is changeable in September, so plan a mix of indoor and outdoor activities and exploring, and pack for every eventuality.
Can you sunbathe in San Jose in September?
September is warm in San Jose. You may enjoy some beach or pool time in the day, but pack something a tad warmer for the evening.
Is San Jose rainy in September?
San Jose is often rainy in September. You may get a bit damp when outside, so pack an umbrella, and maybe even a raincoat.
Is it sunny in San Jose in September?
Usually, it’s not very sunny in San Jose in September, often it’s pretty cloudy. Pack for any eventuality; layering can help reduce the number of bulky items needed.
For this page, we’ve looked at the typical weather in San Jose, based on historical hourly weather data from January 1, 1979, to December 31, 2022.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.