Last updated: June 24, 2025
In April, the average temperature in Grand Coulee, United States hovers around 9°C (48°F). Expect a wide range, with lows dipping to a brisk -4°C (26°F) and highs reaching a pleasant 26°C (78°F). During this period, you'll encounter about 39 mm (1.6 in) of precipitation spread over 7 days. The air tends to be quite humid, with an average humidity level of 82%, so be prepared for a damp atmosphere!
In April in Grand Coulee, the average temperature is 9°C (48°F), with maximums reaching 26°C (78°F) and minimums dropping as low as -4°C (26°F). Travelers should be prepared for a wide range of temperatures, making layers and versatile clothing essential for comfort during their stay.
In Grand Coulee in April, the precipitation amount is 39 mm (1.6 in) over the course of 7 days.
In Grand Coulee in April, humidity is 82%. With an average temperature of 9°C (48°F), this humidity feels like a damp chill that seeps into your bones, making it essential to dress in layers for your travels while keeping an umbrella handy for unexpected drizzles.
In Grand Coulee in April, the maximum UV index is 6, which corresponds to a high Exposure Category. The time to burn is approximately 25 minutes. To find the hourly UV index in Grand Coulee, you can refer to this Hourly UV Index in Grand Coulee.
UV Risk Categories
Weather in Grand Coulee varies notably across the year, with each month offering distinct climate conditions. This page compares April’s weather to other months in Grand Coulee, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -2°C (28°F) | 67 mm (2.6 inches) | 85% | low |
| February Weather | -2°C (28°F) | 47 mm (1.9 inches) | 86% | moderate |
| March Weather | 4°C (39°F) | 46 mm (1.8 inches) | 86% | moderate |
| April Weather | 9°C (48°F) | 39 mm (1.6 inches) | 82% | high |
| May Weather | 15°C (59°F) | 37 mm (1.4 inches) | 77% | very high |
| June Weather | 20°C (68°F) | 13 mm (0.5 inches) | 79% | very high |
| July Weather | 24°C (75°F) | 4 mm (0.1 inches) | 77% | very high |
| August Weather | 23°C (74°F) | 8 mm (0.3 inches) | 62% | very high |
| September Weather | 17°C (62°F) | 24 mm (1.0 inches) | 60% | high |
| October Weather | 8°C (48°F) | 42 mm (1.7 inches) | 80% | moderate |
| November Weather | 3°C (37°F) | 51 mm (2.0 inches) | 87% | moderate |
| December Weather | -2°C (29°F) | 57 mm (2.2 inches) | 86% | low |