May weather forecastHercules, CA
May
Weather in May
The last month of the spring, May, is an agreeable month in Hercules, California, with an average temperature ranging between max 69.3°F (20.7°C) and min 50.5°F (10.3°C).Temperature
Hercules transitions into May recording an average high-temperature of an agreeable 69.3°F (20.7°C), closely aligning with the preceding month's temperature. In the month of May, the nighttime temperature in Hercules dips to a steady average of 50.5°F (10.3°C).Humidity
In May, the average relative humidity in Hercules is 69%.Rainfall
In Hercules, in May, it is raining for 4.3 days, with typically 0.55" (14mm) of accumulated precipitation. In Hercules, during the entire year, the rain falls for 72.2 days and collects up to 12.83" (326mm) of precipitation.Ocean temperature
In May, the average ocean temperature is 53.1°F (11.7°C).Note: It is life-risking to swim in 53.1°F (11.7°C). Briefly staying in 55.4°F (13°C) waters feels unsettling, and temperatures below 50°F (10°C) might result in cold shock and loss of breath control, hinging on personal endurance.
Daylight
In Hercules, the average length of the day in May is 14h and 15min.On the first day of May in Hercules, California, sunrise is at 6:11 am and sunset at 8:00 pm. On the last day of the month, sunrise is at 5:48 am and sunset at 8:25 pm PDT.
Sunshine
In Hercules, California, the average sunshine in May is 10.6h.UV index
The months with the highest UV index in Hercules, California, are April through September, with an average maximum UV index of 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for the ordinary person.Note: The UV index of 5 in May translates into these instructions:
Undertake precautions - Guarding against sun damage is counselled. Avoiding the Sun during its peak radiation time around midday is a healthy practice. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Hercules, CA
- Average high temperature in May: 69.3°F
The warmest month (with the highest average high temperature) is September (77.5°F).
The month with the lowest average high temperature is December (55.4°F).
- Average low temperature in May: 50.5°F
The month with the highest average low temperature is August (56.8°F).
The coldest months (with the lowest average low temperature) are January and December (43.9°F).
Average pressure in May
Hercules, 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
Hercules, CA
- Average wind speed in May: 7.5mph
The windiest month (with the highest average wind speed) is May (7.5mph).
The calmest month (with the lowest average wind speed) is November (4.8mph).
Average humidity in May
Hercules, CA
- Average humidity in May: 69%
The month with the highest relative humidity is March (74%).
The months with the lowest relative humidity are September and October (63%).
Average rainfall in May
Hercules, CA
- Average rainfall in May: 0.55"
The wettest month (with the highest rainfall) is February (2.76").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in May
Hercules, CA
- Average rainfall days in May: 4.3 days
The month with the highest number of rainy days is March (12.6 days).
The month with the least rainy days is August (1.1 days).
Average sea temperature in May
Hercules, CA
- Average sea temperature in May: 53°F
The best month for swimming (with the highest average sea temperature) is September (57°F).
The coldest month (with the lowest average sea temperature) is April (52.6°F).
Average daylight in May /
Average sunshine in May
Hercules, CA
- Average daylight in May: 14h and 12min
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
Hercules, CA
- Average sunshine days in May: 24.3 days
The month with the most sunshine days is August (27.3 days).
The month with the least sunshine days is March (16.4 days).
Average UV index in May
Hercules, CA
- Average UV index in May: 5
The months with the highest UV index are April, May, June, July, August and September (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in May
Hercules, CA
- Average cloud cover in May: 26
The month with the most cloud cover is March (Cloud cover 37).
The month with the least cloud cover is July (Cloud cover 12).
Average visibility in May
Hercules, 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).
