August weather forecastMerrimac, IA
August
Weather in August
The last month of the summer, August, is another warm month in Merrimac, Iowa, with an average temperature varying between 81.7°F (27.6°C) and 63.3°F (17.4°C).Temperature
Merrimac's weather in August, with an average high-temperature of a still warm 81.7°F (27.6°C), subtly shifts from July's 82.4°F (28°C). Throughout the month of August, Merrimac observes an average nighttime temperature of 63.3°F (17.4°C).Heat index
For most parts of August, the heat index is evaluated at a tropical 87.8°F (31°C). With unrelenting exposure and activity, one might experience exhaustion, leading to potential heat cramps.In terms of the heat index, values are set with light wind and shade conditions in mind. If directly exposed to the sun, the heat index could rise by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'feels like', integrates the air's temperature and its humidity to showcase the felt temperature by people. The influence of weather is personal, differing among a variety of individuals based on differences in body mass, stature, and the level of physical activity. It is important to note that direct sunlight can intensify the weather impact, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for children. Children often lack awareness of the importance of taking breaks and rehydrating. The feeling of thirst is a late indication of dehydration, so maintaining hydration, especially during long periods of physical activity, is critical.
Humidity
The average relative humidity in August is 79%.Rainfall
In August, the rain falls for 13.1 days. Throughout August, 2.2" (56mm) of precipitation is accumulated. In Merrimac, Iowa, during the entire year, the rain falls for 140.1 days and collects up to 29.92" (760mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
In August, the average length of the day is 13h and 46min.On the first day of the month, sunrise is at 6:03 am and sunset at 8:22 pm. On the last day of August, sunrise is at 6:33 am and sunset at 7:40 pm CDT.
Sunshine
In Merrimac, the average sunshine in August is 9.9h.UV index
June through August, with an average maximum UV index of 6, are months with the highest UV index. A UV Index of 6 to 7 symbolizes a high health hazard from unsafe exposure to UV radiation for the ordinary person.Note: A daily maximum UV index of 6 in August translates into the following instructions:
Dodge overexposure. Fair-skinned people can get singed in less than 20 minutes. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in August
Merrimac, IA
- Average high temperature in August: 81.7°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 (29.7°F).
- Average low temperature in August: 63.3°F
The month with the highest average low temperature is July (65.3°F).
The coldest month (with the lowest average low temperature) is January (17.4°F).
Average pressure in August
Merrimac, IA
- Average pressure in August: 29.97"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in August
Merrimac, IA
- Average wind speed in August: 6.9mph
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 (6.9mph).
Average humidity in August
Merrimac, IA
- Average humidity in August: 79%
The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall in August
Merrimac, IA
- Average rainfall in August: 2.2"
The wettest month (with the highest rainfall) is May (4.29").
The driest months (with the least rainfall) are February and December (1.38").
Average rainfall days in August
Merrimac, IA
- Average rainfall days in August: 13.1 days
The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is February (4.6 days).
Average snowfall in August
Merrimac, IA
- Average snowfall in August: 0"
The month with the highest snowfall is January (4.76").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in August
Merrimac, IA
- Average snowfall days in August: 0 days
The month with the highest number of snowfall days is January (9.6 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in August /
Average sunshine in August
Merrimac, IA
- Average daylight in August: 13h and 48min
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 August: 9h and 54min
The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days in August
Merrimac, IA
- Average sunshine days in August: 14.8 days
The month with the most sunshine days is October (18.4 days).
The month with the least sunshine days is May (10.6 days).
Average UV index in August
Merrimac, IA
- Average UV index in August: 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 August
Merrimac, IA
- Average cloud cover in August: 31
The month with the most cloud cover is January (Cloud cover 56).
The months with the least cloud cover are July, August and September (Cloud cover 31).
Average visibility in August
Merrimac, IA
- Average visibility in August: 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).
