May weather forecast
Port Costa, CA

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Weather in May

May, the last month of the spring in Port Costa, is a pleasant month, with an average temperature varying between 71.1°F (21.7°C) and 49.8°F (9.9°C).

Temperature

Port Costa's weather, upon May's arrival, documents an average high-temperature of an agreeable 71.1°F (21.7°C), nearly identical to the prior month. Port Costa throughout May, experiences an average nighttime temperature of 49.8°F (9.9°C).

Humidity

In Port Costa, the average relative humidity in May is 66%.

Rainfall

In Port Costa, in May, it is raining for 3.6 days, with typically 0.28" (7mm) of accumulated precipitation. Throughout the year, in Port Costa, California, there are 56.9 rainfall days, and 4.88" (124mm) of precipitation is accumulated.

Daylight

In May, the average length of the day is 14h and 15min.
On the first day of the month, sunrise is at 6:11 am and sunset at 8:00 pm. On the last day of May, sunrise is at 5:47 am and sunset at 8:25 pm PDT.

Sunshine

The average sunshine in May is 10.8h.

UV index

The average daily maximum UV index in May is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for the ordinary person.
Note: The average daily UV index of 5 in May transforms into the following instructions:
Take precautions - Protection against skin and eye damage is obliged. Around midday, solar radiation is most harmful; hence, exposure should be limited. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays.
Updated: Aug 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are May temperatures?

During May, Port Costa experiences an average high-temperature of 71.1°F (21.7°C) and a low-temperature of 49.8°F (9.9°C).

What is the average humidity in May?

In Port Costa, the average relative humidity in May is 66%.

How much does it rain in May?

In Port Costa, during May, the rain falls for 3.6 days and regularly aggregates up to 0.28" (7mm) of precipitation.

How many hours of daylight does Port Costa have in May?

In Port Costa, the average day length in May is 14h and 15min.

When is the sunrise / sunset in May?

In May, on the first day of the month, sunrise is at 6:11 am and sunset at 8:00 pm. On the last day of the month, sunrise is at 5:47 am and sunset at 8:25 pm PDT.

How many hours of sunshine does Port Costa have in May?

In Port Costa, the average sunshine duration in May is 10.8h.

What is the UV index intensity in May?

In May, the average daily maximum UV index in Port Costa is 5. A UV Index of 3 to 5 symbolizes a moderate health threat from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in May
Port Costa, CA

Average temperature in May - Port Costa, CA
  • Average high temperature in May: 71.1°F

The warmest months (with the highest average high temperature) are July and September (80.1°F).
The month with the lowest average high temperature is December (55.4°F).

  • Average low temperature in May: 49.8°F

The month with the highest average low temperature is August (56.5°F).
The coldest month (with the lowest average low temperature) is January (43°F).

Average pressure in May
Port Costa, CA

Average pressure in May - Port Costa, CA
  • Average pressure in May: 29.97"Hg

The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

Average wind speed in May
Port Costa, CA

Average wind speed in May - Port Costa, CA
  • Average wind speed in May: 7.1mph

The windiest month (with the highest average wind speed) is May (7.1mph).
The calmest month (with the lowest average wind speed) is November (4.6mph).

Average humidity in May
Port Costa, CA

Average humidity in May - Port Costa, CA
  • Average humidity in May: 66%

The month with the highest relative humidity is March (75%).
The months with the lowest relative humidity are September and October (60%).

Average rainfall in May
Port Costa, CA

Average rainfall in May - Port Costa, CA
  • Average rainfall in May: 0.28"

The wettest month (with the highest rainfall) is February (1.14").
The driest months (with the least rainfall) are July and August (0.04").

Average rainfall days in May
Port Costa, CA

Average rainfall days in May - Port Costa, CA
  • Average rainfall days in May: 3.6 days

The month with the highest number of rainy days is March (10.2 days).
The month with the least rainy days is August (0.9 days).

Average daylight in May /
Average sunshine in May
Port Costa, CA

Average daylight in May / Average sunshine in May - Port Costa, CA
  • Average daylight in May: 14h and 1min

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 5min

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 42min).

Average sunshine days in May
Port Costa, CA

Average sunshine days in May - Port Costa, CA
  • Average sunshine days in May: 24.3 days

The month with the most sunshine days is July (27.2 days).
The month with the least sunshine days is March (18.8 days).

Average UV index in May
Port Costa, CA

Average UV index in May - Port Costa, 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
Port Costa, CA

Average cloud cover in May - Port Costa, CA
  • Average cloud cover in May: 24

The month with the most cloud cover is March (Cloud cover 37).
The month with the least cloud cover is July (Cloud cover 9).

Average visibility in May
Port Costa, CA

Average visibility in May - Port Costa, 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).

Port Costa, California, USA

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