December weather forecast
Ronkonkoma, NY

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Weather in December

The first month of the winter, December, is also a frosty month in Ronkonkoma, New York, with an average temperature varying between 6.7°C (44.1°F) and 2.9°C (37.2°F).

Temperature

December's arrival aligns with a minor decrease in average high-temperatures, from November's cool 11.3°C (52.3°F) to a frosty 6.7°C (44.1°F). A steady low-temperature average of 2.9°C (37.2°F) is logged during December, reflecting a modest dip from daytime readings.

Humidity

The average relative humidity in December is 74%.

Rainfall

The month with the most rainfall in Ronkonkoma is December, when the rain falls for 12.3 days and typically aggregates up to 95mm (3.74") of precipitation.

Snowfall

January through March, May, October and December are months with snowfall. December is the first month it typically snows. Throughout December, in the average 2.4 snowfall days, it receives 31mm (1.22") of snow. In Ronkonkoma, New York, during the entire year, snow falls for 14.7 days and aggregates up to 156mm (6.14") of snow.

Daylight

With an average of 9h and 18min of daylight, December has the shortest days of the year.
On the first day of the month, sunrise is at 6:58 am and sunset at 4:25 pm. On the last day of December, sunrise is at 7:16 am and sunset at 4:34 pm EST.

Sunshine

In December, the average sunshine in Ronkonkoma is 4.9h.

UV index

January through March and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index value of 2, and less, symbolizes a minimal health hazard from exposure to the Sun's UV radiation for average individuals.
Note: A daily high UV index of 2 in December leads to these guidelines:
Children, babies, and those with sensitive skin should always be shielded from long periods of sun exposure. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation. Alert! The snow's reflection can amplify the UV radiation of the Sun nearly twice.
Updated: Aug 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in December?

December temperatures vary between a high-temperature of 6.7°C (44.1°F) and a low-temperature of 2.9°C (37.2°F).

What is the average humidity in December in Ronkonkoma?

In December, the average relative humidity in Ronkonkoma is 74%.

What is the wettest month?

The month with the most rainfall is December, when the rain falls for 12.3 days and typically aggregates up to 95mm (3.74") of precipitation.

How many days does it rain in December?

In December, the rain falls for 12.3 days. Throughout December, 95mm (3.74") of precipitation is accumulated.

When does it start to snow?

December is the first month it typically snows. Throughout December, in the average 2.4 snowfall days, it receives 31mm (1.22") of snow.

What is the month with the shortest days?

With an average of 9h and 18min of daylight, December has the shortest days of the year.

How many hours of daylight does Ronkonkoma have in December?

In Ronkonkoma, the average day length in December is 9h and 19min.

When is the sunrise / sunset in December?

On the first day of December, sunrise is at 6:58 am and sunset at 4:25 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 4:34 pm EST.

How long on average sun shines in December?

In Ronkonkoma, the average sunshine duration in December is 4.9h.

What are the months with the lowest UV index?

The months with the lowest UV index are January through March and December, with an average maximum UV index of 2.

What is the UV index intensity in December?

In Ronkonkoma, the average daily maximum UV index in December is 2. A UV Index value of 2, and less, symbolizes a minimal hazard to health from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover

Average temperature in December
Ronkonkoma, NY

Average temperature in December - Ronkonkoma, NY
  • Average high temperature in December: 6.7°C

The warmest month (with the highest average high temperature) is August (25.6°C).
The month with the lowest average high temperature is January (3.3°C).

  • Average low temperature in December: 2.9°C

The month with the highest average low temperature is August (22.1°C).
The coldest month (with the lowest average low temperature) is January (-1°C).

Average pressure in December
Ronkonkoma, NY

Average pressure in December - Ronkonkoma, NY
  • Average pressure in December: 1018mbar

The month with the highest atmospheric pressure is November (1019mbar).
The month with the lowest atmospheric pressure is June (1013.6mbar).

Average wind speed in December
Ronkonkoma, NY

Average wind speed in December - Ronkonkoma, NY
  • Average wind speed in December: 21.5km/h

The windiest month (with the highest average wind speed) is January (22.2km/h).
The calmest months (with the lowest average wind speed) are July and August (14.5km/h).

Average humidity in December
Ronkonkoma, NY

Average humidity in December - Ronkonkoma, NY
  • Average humidity in December: 74%

The months with the highest relative humidity are May and June (78%).
The month with the lowest relative humidity is November (71%).

Average rainfall in December
Ronkonkoma, NY

Average rainfall in December - Ronkonkoma, NY
  • Average rainfall in December: 95mm

The wettest month (with the highest rainfall) is December (95mm).
The driest month (with the least rainfall) is January (55mm).

Average rainfall days in December
Ronkonkoma, NY

Average rainfall days in December - Ronkonkoma, NY
  • Average rainfall days in December: 12.3 days

The month with the highest number of rainy days is July (17.7 days).
The month with the least rainy days is January (8.3 days).

Average snowfall in December
Ronkonkoma, NY

Average snowfall in December - Ronkonkoma, NY
  • Average snowfall in December: 31mm

The month with the highest snowfall is March (54mm).
The months with the least snowfall are April, June, July, August, September and November (0mm).

Average snowfall days in December
Ronkonkoma, NY

Average snowfall days in December - Ronkonkoma, NY
  • Average snowfall days in December: 2.4 days

The month with the highest number of snowfall days is February (4.6 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Ronkonkoma, NY

Average daylight in December / Average sunshine in December - Ronkonkoma, NY
  • 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 5min

The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).

Average sunshine days in December
Ronkonkoma, NY

Average sunshine days in December - Ronkonkoma, NY
  • Average sunshine days in December: 16.9 days

The month with the most sunshine days is November (18.8 days).
The month with the least sunshine days is July (11.3 days).

Average UV index in December
Ronkonkoma, NY

Average UV index in December - Ronkonkoma, NY
  • Average UV index in December: 2

The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, March and December (UV index 2).

Average cloud cover in December
Ronkonkoma, NY

Average cloud cover in December - Ronkonkoma, NY
  • Average cloud cover in December: 48

The month with the most cloud cover is December (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 27).

Average visibility in December
Ronkonkoma, NY

Average visibility in December - Ronkonkoma, NY
  • Average visibility in December: 9km

The months with the highest visibility are April, June, July, August, September, October and November (10km).
The months with the lowest visibility are January, February, March, May and December (9km).

Ronkonkoma, New York, USA

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