Contents
- Weather in May
- Frequently asked questions
- Average temperature in May
- Average pressure in May
- Average wind speed in May
- Average humidity in May
- Average rainfall in May
- Average rainfall days in May
- Average daylight in May
- Average sunshine in May
- Average sunshine days in May
- Average UV index in May
- Average cloud cover in May
- Average visibility in May
Weather in May
Temperature
May notes an average high-temperature of a still enjoyable 63.9°F (17.7°C), subtly differing from April's 62.2°F (16.8°C). Throughout the month of May, San Mateo observes an average nighttime temperature of 50.7°F (10.4°C).Humidity
In San Mateo, the average relative humidity in May is 75%.Rainfall
May is the last month it rains. During 2.5 rainfall days, in May, San Mateo aggregates 0.16" (4mm) of precipitation. Throughout the year, there are 32.6 rainfall days, and 2.13" (54mm) of precipitation is accumulated.Daylight
In May, the average length of the day is 14h and 13min.On the first day of the month, sunrise is at 6:12 am and sunset at 7:59 pm. On the last day of May, sunrise is at 5:49 am and sunset at 8:24 pm PDT.
Sunshine
In San Mateo, the average sunshine in May is 10.7h.UV index
The average daily maximum UV index in May is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for ordinary individuals.Note: During May, 4 as the daily maximum UV index converts into the following advice:
Ensure safety - Recommendations to avert sunburn are presented. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are May temperatures?
What is the average humidity in May?
What is the last month it rains?
What is the average length of the day in May?
When is the sunrise / sunset in May?
How many hours of sunshine does San Mateo have in May?
What is the UV index intensity in May?
Average temperature in May
San Mateo, CA
- Average high temperature in May: 63.9°F
The warmest months (with the highest average high temperature) are August and September (71.2°F).
The month with the lowest average high temperature is December (55.8°F).
- Average low temperature in May: 50.7°F
The month with the highest average low temperature is September (56.7°F).
The coldest month (with the lowest average low temperature) is January (46.9°F).
Average pressure in May
San Mateo, CA
- Average pressure in May: 29.98"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is September (29.92"Hg).
Average wind speed in May
San Mateo, CA
- Average wind speed in May: 7.8mph
The windiest month (with the highest average wind speed) is April (8mph).
The calmest months (with the lowest average wind speed) are August, September and October (5.9mph).
Average humidity in May
San Mateo, CA
- Average humidity in May: 75%
The months with the highest relative humidity are March and August (76%).
The months with the lowest relative humidity are October and November (70%).
Average rainfall in May
San Mateo, CA
- Average rainfall in May: 0.16"
The wettest month (with the highest rainfall) is February (0.55").
The driest months (with the least rainfall) are June, July and August (0").
Average rainfall days in May
San Mateo, CA
- Average rainfall days in May: 2.5 days
The month with the highest number of rainy days is March (6.8 days).
The month with the least rainy days is July (0.3 days).
Average daylight in May /
Average sunshine in May
San Mateo, CA
- Average daylight in May: 14h and 1min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in May: 10h and 4min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 54min).
Average sunshine days in May
San Mateo, CA
- Average sunshine days in May: 27.6 days
The month with the most sunshine days is July (30.4 days).
The month with the least sunshine days is February (23.3 days).
Average UV index in May
San Mateo, CA
- Average UV index in May: 4
The months with the highest UV index are June, July, August and September (UV index 5).
The months with the lowest UV index are February and December (UV index 3).
Average cloud cover in May
San Mateo, CA
- Average cloud cover in May: 26
The month with the most cloud cover is March (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 11).
Average visibility in May
San Mateo, CA
- Average visibility in May: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
San Mateo, California, USA
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