Last updated: June 24, 2025
In December, the average temperature in Sayville, United States hovers around 5°C (42°F). Expect chilly moments, as the minimum temperature can dip to -9°C (17°F), while the maximum reaches a comfortable 17°C (63°F). Be prepared for some rain too, with 134 mm (5.3 in) of precipitation spread over about 10 days. Coupled with an average humidity of 80%, it's a month that calls for cozy layers and warm beverages!
In December in Sayville, the average temperature is 5°C (42°F). Maximums can reach 17°C (63°F) and minimums can be as low as -9°C (17°F). It's advisable to pack layers and plan for varying weather conditions while traveling.
In Sayville in December, the total precipitation amount reaches 134 mm (5.3 in) over a span of 10 days.
In Sayville in December humidity is 80%. With an average temperature of 5°C (42°F), this humidity feels like a damp chill that can seep into your bones, making outdoor adventures uncomfortable and urging travelers to seek warm shelter often.
In Sayville in December, the maximum UV index is 2, which corresponds to a low exposure category. With this level of UV radiation, the time to burn is approximately 45 minutes. To learn more about the hourly UV index in Sayville, you can visit Hourly UV Index in Sayville.
UV Risk Categories
Weather in Sayville varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Sayville, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 2°C (36°F) | 80 mm (3.1 inches) | 84% | moderate |
| February Weather | 3°C (37°F) | 108 mm (4.3 inches) | 82% | moderate |
| March Weather | 5°C (41°F) | 106 mm (4.2 inches) | 81% | high |
| April Weather | 9°C (49°F) | 125 mm (4.9 inches) | 78% | very high |
| May Weather | 14°C (57°F) | 117 mm (4.6 inches) | 69% | very high |
| June Weather | 20°C (67°F) | 77 mm (3.0 inches) | 69% | very high |
| July Weather | 24°C (75°F) | 113 mm (4.5 inches) | 62% | very high |
| August Weather | 24°C (75°F) | 101 mm (4.0 inches) | 65% | very high |
| September Weather | 21°C (70°F) | 91 mm (3.6 inches) | 68% | very high |
| October Weather | 16°C (62°F) | 137 mm (5.4 inches) | 74% | high |
| November Weather | 10°C (50°F) | 103 mm (4.1 inches) | 82% | moderate |
| December Weather | 5°C (42°F) | 134 mm (5.3 inches) | 80% | low |