Last updated: June 24, 2025
In December, the average temperature in Prosser, United States hovers around 2°C (35°F), making it a chilly time of year. Expect a minimum plunge to -9°C (16°F), but it can also reach a pleasant maximum of 20°C (68°F). During this month, precipitation averages 31 mm (1.2 in) over 7 days, and with an average humidity level of 86%, be prepared for a damp atmosphere.
In December in Prosser, the average temperature is 2°C (35°F). The maximum can reach up to 20°C (68°F), while the minimum can drop as low as -9°C (16°F). Travelers should be prepared for a wide range of temperatures, ensuring they pack accordingly for both mild and chilly days.
In Prosser in December, the precipitation amount is 31 mm (1.2 in) over the course of 7 days.
In Prosser in December humidity is 86%. With an average temperature of 2°C (35°F), this humidity feels like a damp chill that seeps into your bones, making traveling quite uncomfortable as your clothes cling to you and the cold air cuts through any warmth you try to find.
In Prosser 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 Prosser, you can visit Hourly UV Index in Prosser.
UV Risk Categories
Weather in Prosser varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Prosser, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 1°C (34°F) | 39 mm (1.5 inches) | 85% | low |
| February Weather | 2°C (36°F) | 39 mm (1.5 inches) | 86% | moderate |
| March Weather | 8°C (46°F) | 24 mm (0.9 inches) | 86% | moderate |
| April Weather | 13°C (55°F) | 22 mm (0.9 inches) | 82% | high |
| May Weather | 19°C (66°F) | 15 mm (0.6 inches) | 77% | very high |
| June Weather | 23°C (74°F) | 6 mm (0.2 inches) | 79% | very high |
| July Weather | 27°C (81°F) | 1 mm (0.0 inches) | 77% | very high |
| August Weather | 27°C (80°F) | 4 mm (0.1 inches) | 62% | very high |
| September Weather | 20°C (69°F) | 9 mm (0.3 inches) | 60% | high |
| October Weather | 12°C (53°F) | 24 mm (1.0 inches) | 80% | moderate |
| November Weather | 5°C (42°F) | 31 mm (1.2 inches) | 87% | moderate |
| December Weather | 2°C (35°F) | 31 mm (1.2 inches) | 86% | low |