April weather forecast and climate
Hercules, CA

Weather in April

April, the same as March, is another enjoyable spring month in Hercules, California, with average temperature ranging between min 47.8°F (8.8°C) and max 65.7°F (18.7°C).

Temperature

In April, the average high-temperature is essentially the same as in March - a still comfortable 65.7°F (18.7°C). In April, in Hercules, the average low-temperature is 47.8°F (8.8°C).

Humidity

In April, the average relative humidity in Hercules is 70%.

Rainfall

In Hercules, it is raining for 7.3 days, with typically 0.71" (18mm) 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

With an average ocean temperature of 52.7°F (11.5°C), April is the month with the coldest seawater in Hercules, California.
Note: At temperatures below 50°F (10°C), swimming in a suitably protected swimsuit is feasible; otherwise, cold shock and loss of breathing control are imminent. Even a short swim, without thermal protection, at temperatures around 55.4°F (13°C) is not comfortable.

Daylight

In April, the average length of the day in Hercules is 13.2h.

Sunshine

In April, the average sunshine is 10.3h.

UV index

April through September, with an average maximum UV index of 5, are months with the highest UV index. A UV Index estimate of 3 to 5 represents a medium vulnerability from the exposure to the Sun's UV radiation for ordinary individuals.
Note: The daily maximum UV index of 5 in April interpret into the following advice:
Take precautions. Light skin individuals may get burned in less than 30 minutes. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
[Resources]

FAQ

What is the temperature in April in Hercules?

In Hercules, California, in April, the average high-temperature is 65.7°F (18.7°C), and the average low-temperature is 47.8°F (8.8°C).

What is the average humidity in April in Hercules?

In Hercules, California, the average relative humidity in April is 70%.

How many days does it rain in April in Hercules?

In Hercules, California, during April, the rain falls for 7.3 days and regularly aggregates up to 0.71" (18mm) of precipitation.

What month is the ocean coldest in Hercules?

The month with the coldest seawater in Hercules, California, is April, with an average ocean temperature of 52.7°F (11.5°C).

How cold is the water in April in Hercules?

In April, the average ocean temperature is 52.7°F (11.5°C). Swimming in 52.7°F (11.5°C) is considered dangerous. Unprotected immersion in temperatures below 50°F (10°C) causes quickly maximum intensity cold shock with hyperventilation.

What is the average length of the day in April in Hercules?

In Hercules, California, the average length of the day in April is 13.2h.

How long on average sun shines in April in Hercules?

In April, the average sunshine in Hercules is 10.3h.

What is the month with the highest UV index in Hercules?

April through September, with an average maximum UV index of 5, are months with the highest UV index in Hercules, California.

What is the UV index reading in April in Hercules?

In Hercules, the average daily maximum UV index in April is 5. A UV Index estimate of 3 to 5 represents a medium hazard to health from the exposure to the Sun's UV rays.

Average temperature in April
Hercules, CA

Average temperature in April - Hercules, CA
  • Average high temperature in April: 65.7°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 April: 47.8°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).

[Resources]

Average pressure in April
Hercules, CA

Average pressure in April - Hercules, CA
  • Average pressure in April: 30.03"

The month with the highest atmospheric pressure is January (30.13").
Months with the lowest atmospheric pressure are June, August and September (29.92").

[Resources]

Average wind speed in April
Hercules, CA

Average wind speed in April - Hercules, CA
  • Average wind speed in April: 6.8mph

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).

[Resources]

Average humidity in April
Hercules, CA

Average humidity in April - Hercules, CA
  • Average humidity in April: 70%

The month with the highest relative humidity is March (74%).
Months with the lowest relative humidity are September and October (63%).

[Resources]

Average rainfall in April
Hercules, CA

Average rainfall in April - Hercules, CA
  • Average rainfall in April: 0.71"

The wettest month (with the highest rainfall) is February (2.76").
The driest months (with the least rainfall) are July and August (0.04").

[Resources]

Average rainfall days in April
Hercules, CA

Average rainfall days in April - Hercules, CA
  • Average rainfall days in April: 7.3 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).

[Resources]

Average sea temperature in April
Hercules, CA

Average sea temperature in April - Hercules, CA
  • Average sea temperature in April: 52.6°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).

[Resources]

Average daylight in April /
Average sunshine in April
Hercules, CA

Average daylight in April / Average sunshine in April - Hercules, CA
  • Average daylight in April: 13.2h

The month with the longest days is June (Average daylight: 14.8h).
The month with the shortest days is December (Average daylight: 9.6h).

  • Average sunshine in April: 10.3h

The month with the most sunshine is July (Average sunshine: 11.9h).
The month with the least sunshine is December (Average sunshine: 5.7h).

[Resources]

Average sunshine days in April
Hercules, CA

Average sunshine days in April - Hercules, CA
  • Average sunshine days in April: 21.6 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).

[Resources]

Average UV index in April
Hercules, CA

Average UV index in April - Hercules, CA
  • Average UV index in April: 5

Months with the highest UV index are April, May, June, July, August and September (UV index 5).
Months with the lowest UV index are January, February, November and December (UV index 3).

[Resources]

Average cloud cover in April
Hercules, CA

Average cloud cover in April - Hercules, CA
  • Average cloud cover in April: 28

The month with the most cloud cover is March (Cloud cover 37).
The month with the least cloud cover is July (Cloud cover 12).

[Resources]

Average visibility in April
Hercules, CA

Average visibility in April - Hercules, CA
  • Average visibility in April: 6mi

Months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

[Resources]