May weather forecast
Sully, IA

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Weather in May

May, the last month of the spring in Sully, is a pleasant month, with an average temperature ranging between min 52.5°F (11.4°C) and max 69.3°F (20.7°C).

Temperature

With the onset of May, Sully experiences a temperature shift, with the average high-temperature moving from a refreshing 58.8°F (14.9°C) in April to a pleasant 69.3°F (20.7°C). During the month of May, Sully's nighttime temperature lowers to an average of 52.5°F (11.4°C).

Humidity

In Sully, the average relative humidity in May is 78%.

Rainfall

The month with the most rainfall in Sully is May, when the rain falls for 14.7 days and typically aggregates up to 2.13" (54mm) of precipitation.

Snowfall

January through May, October through December are months with snowfall in Sully, Iowa. May is the last month it regularly snows in Sully. During 0.2 snowfall days, in May, Sully aggregates 0.04" (1mm) of snow. In Sully, during the entire year, snow falls for 28.8 days and aggregates up to 5.28" (134mm) of snow.

Daylight

In May, the average length of the day in Sully is 14h and 33min.
On the first day of the month, sunrise is at 6:06 am and sunset at 8:09 pm. On the last day of May, sunrise is at 5:39 am and sunset at 8:38 pm CDT.

Sunshine

In Sully, the average sunshine in May is 8.6h.

UV index

In Sully, Iowa, the average daily maximum UV index in May is 5. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for ordinary individuals.
Note: A maximum high UV index of 5 in May translates into the following recommendations:
Take necessary precautions - Protection from skin and eye injury is mandatory. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. A hat with a broad brim is indispensable, filtering out up to half of UV rays. Alert! The snow's reflection can amplify the UV radiation of the Sun nearly twice.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the temperature in May in Sully?

The high-temperature, in May, in Sully, records 69.3°F (20.7°C), while the low-temperature is 52.5°F (11.4°C).

What is the average humidity in May in Sully?

In Sully, the average relative humidity in May is 78%.

What is the rainiest month in Sully?

May is the month with the most rainfall in Sully, Iowa. Rain falls for 14.7 days and accumulates 2.13" (54mm) of precipitation.

How much does it rain in Sully in May?

In Sully, during May, the rain falls for 14.7 days and regularly aggregates up to 2.13" (54mm) of precipitation.

What is the last month it snows in Sully?

May is the last month it regularly snows in Sully. During 0.2 snowfall days, in May, Sully aggregates 0.04" (1mm) of snow.

What is the average length of the day in May in Sully?

The average day length in May in Sully is 14h and 33min.

What time are sunrise and sunset in May in Sully?

In May, on the first day of the month, sunrise is at 6:06 am and sunset at 8:09 pm. On the last day of the month, in Sully, Iowa, sunrise is at 5:39 am and sunset at 8:38 pm CDT.

How long on average sun shines in May in Sully?

In Sully, the average sunshine duration in May is 8.6h.

What is the UV index intensity in May in Sully?

In May, the average daily maximum UV index in Sully, Iowa, is 5. A UV Index value of 3 to 5 symbolizes a medium hazard to health from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in May
Sully, IA

Average temperature in May - Sully, IA
  • Average high temperature in May: 69.3°F

The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (27.1°F).

  • Average low temperature in May: 52.5°F

The month with the highest average low temperature is July (64.8°F).
The coldest month (with the lowest average low temperature) is January (14.4°F).

Average pressure in May
Sully, IA

Average pressure in May - Sully, IA
  • Average pressure in May: 29.93"Hg

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).

Average wind speed in May
Sully, IA

Average wind speed in May - Sully, IA
  • Average wind speed in May: 9mph

The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest months (with the lowest average wind speed) are July and August (7mph).

Average humidity in May
Sully, IA

Average humidity in May - Sully, IA
  • Average humidity in May: 78%

The month with the highest relative humidity is January (84%).
The month with the lowest relative humidity is October (71%).

Average rainfall in May
Sully, IA

Average rainfall in May - Sully, IA
  • Average rainfall in May: 2.13"

The wettest month (with the highest rainfall) is May (2.13").
The driest months (with the least rainfall) are January, February and December (0.39").

Average rainfall days in May
Sully, IA

Average rainfall days in May - Sully, IA
  • Average rainfall days in May: 14.7 days

The month with the highest number of rainy days is May (14.7 days).
The month with the least rainy days is February (3.4 days).

Average snowfall in May
Sully, IA

Average snowfall in May - Sully, IA
  • Average snowfall in May: 0.04"

The month with the highest snowfall is January (1.73").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in May
Sully, IA

Average snowfall days in May - Sully, IA
  • Average snowfall days in May: 0.2 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 May /
Average sunshine in May
Sully, IA

Average daylight in May / Average sunshine in May - Sully, IA
  • Average daylight in May: 14h and 3min

The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).

  • Average sunshine in May: 8h and 4min

The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).

Average sunshine days in May
Sully, IA

Average sunshine days in May - Sully, IA
  • Average sunshine days in May: 13.6 days

The month with the most sunshine days is December (22.9 days).
The month with the least sunshine days is June (12.2 days).

Average UV index in May
Sully, IA

Average UV index in May - Sully, IA
  • Average UV index in May: 5

The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).

Average cloud cover in May
Sully, IA

Average cloud cover in May - Sully, IA
  • Average cloud cover in May: 42

The month with the most cloud cover is January (Cloud cover 55).
The months with the least cloud cover are July and September (Cloud cover 30).

Average visibility in May
Sully, IA

Average visibility in May - Sully, IA
  • Average visibility in May: 6mi

The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).

Sully, Iowa, USA

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