May weather forecastCastro Valley, CA

May

Weather in May

The last month of the spring, May, is an agreeable month in Castro Valley, California, with temperature in the range of an average low of 49.1°F (9.5°C) and an average high of 70.3°F (21.3°C).

Temperature

With the arrival of May, Castro Valley's average high-temperature registers at an agreeable 70.3°F (21.3°C), indicating a subtle variation from the previous month. Castro Valley encounters a steady low-temperature average of 49.1°F (9.5°C) throughout the month of May.

Humidity

In May, the average relative humidity is 67%.

Rainfall

In Castro Valley, in May, it is raining for 4.3 days, with typically 0.51" (13mm) of accumulated precipitation. In Castro Valley, during the entire year, the rain falls for 69.2 days and collects up to 11.1" (282mm) of precipitation.

Daylight

The average length of the day in May is 14h and 13min.
On the first day of the month, sunrise is at 6:11 am and sunset at 7:59 pm. On the last day of May, sunrise is at 5:48 am and sunset at 8:24 pm PDT.

Sunshine

In Castro Valley, the average sunshine in May is 10.9h.

UV index

In May, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for the average person.
Note: In May, the maximum UV index of 5 transforms into these recommendations:
Take necessary precautions - Defending against sun damage is advocated. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays.

Updated: Feb 9, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

An average high-temperature, in May, in Castro Valley, is 70.3°F (21.3°C) and the average low-temperature is 49.1°F (9.5°C).

In May, the average relative humidity in Castro Valley, California, is 67%.

In May, in Castro Valley, California, the rain falls for 4.3 days. Throughout May, 0.51" (13mm) of precipitation is accumulated.

In May, the average day length in Castro Valley is 14h and 13min.

In May, on the first day of the month, sunrise is at 6:11 am and sunset at 7:59 pm. On the last day of the month, in Castro Valley, sunrise is at 5:48 am and sunset at 8:24 pm PDT.

In Castro Valley, California, the average sunshine duration in May is 10.9h.

In May, the average daily maximum UV index in Castro Valley, California, is 5. A UV Index of 3 to 5 symbolizes a moderate vulnerability from unsafe exposure to Sun's UV rays.

Today

Tomorrow

Long-term

Year J F M A May J J A S O N D

Apr

May

Jun

Average high temperature

66.2°F

70.3°F

77°F

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

6.9mph

7.3mph

7mph

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

Average daylight

Average sunshine

Average sunshine days

22.1

27.3

Average UV index

Average cloud cover

Average visibility

Average temperature in May
Castro Valley, CA

Average high temperature in May: 70.3°F

The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is December (55.9°F).

Average low temperature in May: 49.1°F

The month with the highest average low temperature is August (56.5°F).
The coldest months (with the lowest average low temperature) are January and December (43.7°F).

Average pressure in May
Castro Valley, CA

Average pressure in May: 29.98"Hg

The month with the highest atmospheric pressure is January (30.14"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).

Average wind speed in May
Castro Valley, CA

Average wind speed in May: 6.6mph

The windiest month (with the highest average wind speed) is May (6.6mph).
The calmest month (with the lowest average wind speed) is November (4.6mph).

Average humidity in May
Castro Valley, CA

Average humidity in May: 67%

The month with the highest relative humidity is March (74%).
The month with the lowest relative humidity is September (61%).

Average rainfall in May
Castro Valley, CA

Average rainfall in May: 0.51"

The wettest month (with the highest rainfall) is February (2.28").
The driest months (with the least rainfall) are July and August (0.04").

Average rainfall days in May
Castro Valley, CA

Average rainfall days in May: 4.3 days

The month with the highest number of rainy days is March (12.4 days).
The month with the least rainy days is August (0.9 days).

Average daylight in May /
Average sunshine in May
Castro Valley, CA

Average daylight in May: 14h and 12min

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 54min

The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 54min).

Average sunshine days in May
Castro Valley, CA

Average sunshine days in May: 26 days

The month with the most sunshine days is August (28.9 days).
The month with the least sunshine days is March (17.3 days).

Average UV index in May
Castro Valley, 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
Castro Valley, CA

Average cloud cover in May: 22

The months with the most cloud cover are March and December (Cloud cover 34).
The month with the least cloud cover is July (Cloud cover 7).

Average visibility in May
Castro Valley, 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).