Contents
- Weather in July
- Frequently asked questions
- Average temperature in July
- Average pressure in July
- Average wind speed in July
- Average humidity in July
- Average rainfall in July
- Average rainfall days in July
- Average snowfall in July
- Average snowfall days in July
- Average daylight in July
- Average sunshine in July
- Average sunshine days in July
- Average UV index in July
- Average cloud cover in July
- Average visibility in July
Weather in July
Temperature
With average high temperatures of 83.1°F (28.4°C) and lows of 65.7°F (18.7°C), July is the warmest month.Heat index
Throughout July, the heat index is evaluated at a hot 91.4°F (33°C). Implement enhanced safety actions, heat cramps and heat exhaustion could occur. Sustained activity might result in heatstroke.The heat index's values are generally associated with conditions in shade and light breezes. Direct sunlight might cause an increase of up to 15 Fahrenheit (8 Celsius) degrees in the heat index.
Note: The heat index, also known as 'real feel' or 'felt air temperature', is a composite of temperature and humidity figures to convey how warm it feels. Metabolic differences, pregnancy status, and the level of physical activity are additional factors influencing an individual's weather perception. Be aware that direct exposure to sunlight increases heat impact and may raise the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for children. Children frequently underestimate the importance of resting and drinking fluids. Thirst is a symptom of advanced dehydration - hence the need to hydrate regularly, especially during protracted physical exercises.
Humidity
In July, the average relative humidity is 81%.Rainfall
In Derby, Iowa, in July, during 13.8 rainfall days, 2.17" (55mm) of precipitation is typically accumulated. In Derby, during the entire year, the rain falls for 131.1 days and collects up to 25.71" (653mm) of precipitation.Snowfall
In Derby, snow does not fall in June through September.Daylight
In Derby, the average length of the day in July is 14h and 46min.On the first day of the month, sunrise is at 5:46 am and sunset at 8:49 pm. On the last day of July, in Derby, sunrise is at 6:09 am and sunset at 8:30 pm CDT.
Sunshine
With an average of 10.2h of sunshine, July has the most sunshine of the year.UV index
The months with the highest UV index in Derby are June through August, with an average maximum UV index of 6. A UV Index of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV rays for ordinary individuals.Note: A daily high UV index of 6 in July leads to these guidelines:
Resist overexposure. Safeguarding from solar damage is indispensable. UV radiation from the Sun is most intense between 10 a.m. and 4 p.m. Try to avoid direct sunlight during this period. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What part of the year is the hottest in Derby?
How hot is it in Derby in July?
What is the average humidity in July in Derby?
How many days does it rain in July in Derby?
When it does not snow in Derby?
What is the average length of the day in July in Derby?
What time are sunrise and sunset in July in Derby?
What month has the most sunshine in Derby?
How long on average sun shines in July in Derby?
What is the month with the highest UV index in Derby?
What is the UV index reading in July in Derby?
Average temperature in July
Derby, IA
- Average high temperature in July: 83.1°F
The warmest month (with the highest average high temperature) is July (83.1°F).
The month with the lowest average high temperature is January (29.3°F).
- Average low temperature in July: 65.7°F
The month with the highest average low temperature is July (65.7°F).
The coldest month (with the lowest average low temperature) is January (16°F).
Average pressure in July
Derby, IA
- Average pressure in July: 29.96"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in July
Derby, IA
- Average wind speed in July: 7.1mph
The windiest month (with the highest average wind speed) is January (10.7mph).
The calmest months (with the lowest average wind speed) are July and August (7.1mph).
Average humidity in July
Derby, IA
- Average humidity in July: 81%
The month with the highest relative humidity is June (83%).
The month with the lowest relative humidity is October (72%).
Average rainfall in July
Derby, IA
- Average rainfall in July: 2.17"
The wettest month (with the highest rainfall) is June (3.74").
The driest month (with the least rainfall) is January (0.94").
Average rainfall days in July
Derby, IA
- Average rainfall days in July: 13.8 days
The month with the highest number of rainy days is May (16.7 days).
The month with the least rainy days is January (4.7 days).
Average snowfall in July
Derby, IA
- Average snowfall in July: 0"
The month with the highest snowfall is February (4.13").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in July
Derby, IA
- Average snowfall days in July: 0 days
The month with the highest number of snowfall days is January (10.2 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in July /
Average sunshine in July
Derby, IA
- Average daylight in July: 14h and 5min
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 18min).
- Average sunshine in July: 10h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in July
Derby, IA
- Average sunshine days in July: 14.1 days
The month with the most sunshine days is November (19.3 days).
The month with the least sunshine days is June (10.7 days).
Average UV index in July
Derby, IA
- Average UV index in July: 6
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in July
Derby, IA
- Average cloud cover in July: 30
The month with the most cloud cover is January (Cloud cover 54).
The months with the least cloud cover are July and August (Cloud cover 30).
Average visibility in July
Derby, IA
- Average visibility in July: 6mi
The months with the highest visibility are February, March, April, May, June, July, September, October, November and December (6mi).
The months with the lowest visibility are January and August (5mi).
Derby, Iowa, USA
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