December weather forecast
Letts, IA

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Weather in December

December, the first month of the winter in Letts, is also an icy month, with an average temperature fluctuating between 23.9°F (-4.5°C) and 34.7°F (1.5°C).

Temperature

Letts's December weather features a mild decline in high-temperatures, reducing from a frosty 47.1°F (8.4°C) in November to an icy 34.7°F (1.5°C). Letts reports a consistent average low-temperature of 23.9°F (-4.5°C) throughout December nights.

Humidity

The average relative humidity in December is 80%.

Rainfall

February and December are months with the least rain in Letts when the rain falls for 7.8 days and typically aggregates up to 1.46" (37mm) of rain.

Snowfall

Months with snowfall in Letts are January through April, October through December. In Letts, Iowa, in December, during 8 snowfall days, 2.2" (56mm) of snow is typically accumulated. In Letts, during the entire year, snow falls for 40.1 days and aggregates up to 16.38" (416mm) of snow.

Daylight

December has the shortest days of the year, with an average of 9h and 18min of daylight.
On the first day of December in Letts, sunrise is at 7:12 am and sunset at 4:36 pm. On the last day of the month, sunrise is at 7:30 am and sunset at 4:45 pm CST.

Sunshine

The average sunshine in December is 4.6h.

UV index

The months with the lowest UV index in Letts, Iowa, are January and December, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a low threat to health from unprotected exposure to Sun's UV rays for the ordinary person.
Note: In December, a daily maximum UV index of 1 leads to the following instructions:
Despite the majority tolerating prolonged sun exposure, those with sensitive skin, infants, and children demand continual protection. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays. On your guard! Snow's reflection can almost double the intensity of the Sun's UV radiation.
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Frequently asked questions

How cold is it in Letts in December?

In Letts, in December, the average high-temperature is 34.7°F (1.5°C), and the average low-temperature is 23.9°F (-4.5°C). In August, the average heat index (a.k.a. 'apparent temperature', 'real feel'), which represents the influence of relative humidity on air temperature, is evaluated at 86°F (30°C).

What is the average humidity in December in Letts?

In Letts, the average relative humidity in December is 80%.

What is the driest month in Letts?

February and December are months with the least rain in Letts when the rain falls for 7.8 days and typically aggregates up to 1.46" (37mm) of rain.

How many days does it rain in December in Letts?

In Letts, Iowa, during December, the rain falls for 7.8 days and regularly aggregates up to 1.46" (37mm) of precipitation.

How many days does it snow in December in Letts?

In Letts, Iowa, in December, during 8 snowfall days, 2.2" (56mm) of snow is typically accumulated.

What is the month with the shortest days in Letts?

The month with the shortest days in Letts, Iowa, is December, with an average of 9h and 18min of daylight.

What is the average length of the day in December in Letts?

In December, the average day length is 9h and 15min.

When is the sunrise / sunset in December in Letts?

On the first day of December in Letts, sunrise is at 7:12 am and sunset at 4:36 pm. On the last day of the month, sunrise is at 7:30 am and sunset at 4:45 pm CST.

How long on average sun shines in December in Letts?

In Letts, the average sunshine duration in December is 4.6h.

What is the month with the lowest UV index in Letts?

January and December, with an average maximum UV index of 1, are months with the lowest UV index.

What is the UV index intensity in December in Letts?

In December, the average daily maximum UV index is 1. A UV Index reading of 2, and below, represents a low health risk from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Letts, IA

Average temperature in December - Letts, IA
  • Average high temperature in December: 34.7°F

The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (28.4°F).

  • Average low temperature in December: 23.9°F

The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (16.3°F).

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Average pressure in December
Letts, IA

Average pressure in December - Letts, IA
  • Average pressure in December: 30.11"Hg

The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

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Average wind speed in December
Letts, IA

Average wind speed in December - Letts, IA
  • Average wind speed in December: 9.8mph

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 (6.8mph).

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Average humidity in December
Letts, IA

Average humidity in December - Letts, IA
  • Average humidity in December: 80%

The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (71%).

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Average rainfall in December
Letts, IA

Average rainfall in December - Letts, IA
  • Average rainfall in December: 1.46"

The wettest month (with the highest rainfall) is May (5").
The driest months (with the least rainfall) are February and December (1.46").

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Average rainfall days in December
Letts, IA

Average rainfall days in December - Letts, IA
  • Average rainfall days in December: 7.8 days

The month with the highest number of rainy days is May (19.7 days).
The months with the least rainy days are January and February (6.3 days).

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Average snowfall in December
Letts, IA

Average snowfall in December - Letts, IA
  • Average snowfall in December: 2.2"

The month with the highest snowfall is January (4.92").
The months with the least snowfall are May, June, July, August and September (0").

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Average snowfall days in December
Letts, IA

Average snowfall days in December - Letts, IA
  • Average snowfall days in December: 8 days

The month with the highest number of snowfall days is January (12.2 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

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Average daylight in December /
Average sunshine in December
Letts, IA

Average daylight in December / Average sunshine in December - Letts, IA
  • Average daylight in December: 9h and 2min

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 December: 4h and 4min

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).

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Average sunshine days in December
Letts, IA

Average sunshine days in December - Letts, IA
  • Average sunshine days in December: 16.8 days

The month with the most sunshine days is November (17.2 days).
The month with the least sunshine days is June (8.3 days).

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Average UV index in December
Letts, IA

Average UV index in December - Letts, IA
  • Average UV index in December: 1

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

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Average cloud cover in December
Letts, IA

Average cloud cover in December - Letts, IA
  • Average cloud cover in December: 52

The month with the most cloud cover is January (Cloud cover 55).
The months with the least cloud cover are August and September (Cloud cover 29).

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Average visibility in December
Letts, IA

Average visibility in December - Letts, IA
  • Average visibility in December: 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).

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Letts, Iowa, USA

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