April weather forecastJohnston, IA
April
Weather in April
April in Johnston offers the full bloom of spring. After the thaw of March, the city basks in longer daylight hours and diminishing snowfall. Nature unfolds in an array of colors, and people step out more frequently to soak up the milder temperature. There is a significant jump in rainfall this month, nourishing the grass and awakening dormant seeds. April's weather heralds new beginnings and the onset of vibrant life in Johnston.Temperature
As April begins, there is an increase in the average high-temperature, moving from a chilly 46.9°F (8.3°C) in March to a moderate 59.4°F (15.2°C). During the month of April, Johnston anticipates a mean low-temperature of 42.4°F (5.8°C).Humidity
In April, the average relative humidity is 72%.Rainfall
In Johnston, during April, the rain falls for 13.1 days and regularly aggregates up to 1.3" (33mm) of precipitation. Throughout the year, there are 114.6 rainfall days, and 15.51" (394mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, October through December. In Johnston, in April, snow falls for 0.8 days, with typically accumulated 0.24" (6mm) of snow. Throughout the year, there are 29.6 snowfall days, and 6.77" (172mm) of snow is accumulated.Daylight
The average length of the day in April is 13h and 22min.On the first day of the month, sunrise is at 6:56 am and sunset at 7:40 pm. On the last day of April, sunrise is at 6:11 am and sunset at 8:12 pm CDT.
Sunshine
In April, the average sunshine is 8.1h.UV index
In April, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for the average person.Note: In April, the UV index of 4 transforms into the following advice:
Preventative actions are necessary - Suggestions to safeguard against sun damage are in order. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes. Observe! Snow reflection can nearly intensify the Sun's UV radiation twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in April
Johnston, IA
- Average high temperature in April: 59.4°F
The warmest month (with the highest average high temperature) is July (82.4°F).
The month with the lowest average high temperature is January (27.9°F).
- Average low temperature in April: 42.4°F
The month with the highest average low temperature is July (65.1°F).
The coldest month (with the lowest average low temperature) is January (14.4°F).
Average pressure in April
Johnston, IA
- Average pressure in April: 29.93"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in April
Johnston, IA
- Average wind speed in April: 10.4mph
The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (7mph).
Average humidity in April
Johnston, IA
- Average humidity in April: 72%
The month with the highest relative humidity is January (83%).
The month with the lowest relative humidity is October (70%).
Average rainfall in April
Johnston, IA
- Average rainfall in April: 1.3"
The wettest months (with the highest rainfall) are May and June (2.52").
The driest month (with the least rainfall) is January (0.47").
Average rainfall days in April
Johnston, IA
- Average rainfall days in April: 13.1 days
The month with the highest number of rainy days is May (16.3 days).
The month with the least rainy days is February (3.5 days).
Average snowfall in April
Johnston, IA
- Average snowfall in April: 0.24"
The month with the highest snowfall is January (2.2").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in April
Johnston, IA
- Average snowfall days in April: 0.8 days
The month with the highest number of snowfall days is January (8.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in April /
Average sunshine in April
Johnston, IA
- Average daylight in April: 13h and 24min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in April: 8h and 6min
The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).
Average sunshine days in April
Johnston, IA
- Average sunshine days in April: 14.8 days
The month with the most sunshine days is December (22.8 days).
The month with the least sunshine days is June (11.2 days).
Average UV index in April
Johnston, IA
- Average UV index in April: 4
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in April
Johnston, IA
- Average cloud cover in April: 44
The month with the most cloud cover is January (Cloud cover 53).
The month with the least cloud cover is September (Cloud cover 28).
Average visibility in April
Johnston, IA
- Average visibility in April: 6mi
The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).





