May weather forecastPetaluma, CA
May
Weather in May
May, the last month of the spring in Petaluma, is another refreshing month, with an average temperature varying between 67.8°F (19.9°C) and 48.9°F (9.4°C).Temperature
May's weather records an average high-temperature of a still comfortable 67.8°F (19.9°C), showing little deviation from April. During May, Petaluma records an average temperature of 48.9°F (9.4°C) at night.Humidity
The average relative humidity in May is 72%.Rainfall
In May, the rain falls for 5.3 days. Throughout May, 0.79" (20mm) of precipitation is accumulated. Throughout the year, there are 71.1 rainfall days, and 15.24" (387mm) of precipitation is accumulated.Daylight
In Petaluma, the average length of the day in May is 14h and 16min.On the first day of May, sunrise is at 6:12 am and sunset at 8:02 pm. On the last day of the month, sunrise is at 5:48 am and sunset at 8:27 pm PDT.
Sunshine
The average sunshine in May is 10.6h.UV index
The average daily maximum UV index in May in Petaluma is 5. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for average individuals.Note: The UV index of 5 in May translates into these instructions:
Undertake protective steps - Obligation to safeguard skin and eyes from harm is in place. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Petaluma, CA
- Average high temperature in May: 67.8°F
The warmest month (with the highest average high temperature) is August (77.9°F).
The month with the lowest average high temperature is December (55.2°F).
- Average low temperature in May: 48.9°F
The month with the highest average low temperature is September (55.2°F).
The coldest month (with the lowest average low temperature) is December (43.2°F).
Average pressure in May
Petaluma, CA
- Average pressure in May: 29.98"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).
Average wind speed in May
Petaluma, CA
- Average wind speed in May: 7mph
The windiest months (with the highest average wind speed) are April and May (7mph).
The calmest month (with the lowest average wind speed) is November (5mph).
Average humidity in May
Petaluma, CA
- Average humidity in May: 72%
The month with the highest relative humidity is March (77%).
The months with the lowest relative humidity are September and October (65%).
Average rainfall in May
Petaluma, CA
- Average rainfall in May: 0.79"
The wettest month (with the highest rainfall) is February (3.5").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in May
Petaluma, CA
- Average rainfall days in May: 5.3 days
The month with the highest number of rainy days is March (12.6 days).
The month with the least rainy days is July (1 days).
Average daylight in May /
Average sunshine in May
Petaluma, CA
- Average daylight in May: 14h and 18min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in May: 10h and 36min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 42min).
Average sunshine days in May
Petaluma, CA
- Average sunshine days in May: 25.1 days
The month with the most sunshine days is July (28.4 days).
The month with the least sunshine days is March (17.2 days).
Average UV index in May
Petaluma, CA
- Average UV index in May: 5
The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in May
Petaluma, CA
- Average cloud cover in May: 26
The month with the most cloud cover is March (Cloud cover 39).
The month with the least cloud cover is July (Cloud cover 10).
Average visibility in May
Petaluma, 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).
