Grand Coulee

Find out the latest weather in Grand Coulee. In this section, we have gathered the most up-to-date data for you: current conditions, detailed forecasts, and clear charts to help you plan your time more effectively.

The climate in Grand Coulee can be described as continental with semi-arid features, characterized by significant seasonal temperature variations. The city clearly experiences four distinct seasons, each with its own characteristics. Overall, the weather here is marked by low precipitation throughout the year.

Summer in Grand Coulee, particularly the months of July and August, is hot and very dry. Average temperatures during this period rise to 24-25°C, with maximums potentially exceeding 30°C, while precipitation is minimal and the number of rainy days is close to zero. Winter (December–February) is cold, with average temperatures around -1°C to -2°C and more frequent, though still light, precipitation. Spring and autumn are transitional seasons with gradual temperature changes and low rainfall.

A key feature of the Grand Coulee climate is the low annual precipitation. Even in the winter months, when the number of days with precipitation reaches its peak (12-13 days in January and December), the actual amount of moisture remains small (about 2 mm). This makes the region quite arid, especially in the summer, when rain becomes a rare occurrence.

In the city of Grand Coulee, located in the USA, there is a distinct change of seasons with significant temperature fluctuations throughout the year. The hottest months are traditionally July, with an average air temperature of around 24.6°C and daytime highs reaching 31.6°C, and August, with an average temperature of 23.8°C and highs up to 30.6°C. In contrast, the coldest period is during winter: in January, the average temperature drops to -1.5°C (with nighttime lows down to -4.2°C), and in December, it falls to -1.9°C (with a minimum of -4.3°C). February is also characterized by sub-zero average temperatures (-1.0°C) and nighttime frosts as low as -5.0°C.

The summer months in Grand Coulee, from June to August, are marked by hot and mostly dry weather. Daytime temperatures are consistently high: in June, the average maximum is 25.8°C, while in July and August, it exceeds 30°C. Nights bring a noticeable chill—average minimum temperatures during this period range from 13.3°C to 17.5°C. This indicates significant diurnal temperature ranges, especially at the height of summer, when the difference between daytime heat and nighttime coolness can exceed 14°C. The low amount of precipitation (0-1 mm per month) confirms the arid nature of the summer season.

The winter period, covering December, January, and February, is characterized by freezing weather. Average daytime temperatures are often near freezing or slightly above (from 0.6°C to 3.0°C), while nighttime temperatures consistently drop below zero, reaching marks from -4.2°C to -5.0°C. Spring (March–May) and autumn (September–October) are transitional seasons with a gradual shift in temperature. In spring, the air temperature rises steadily from an average of 4.1°C in March to a comfortable 15.7°C in May. In autumn, the reverse trend is observed—from a warm 18.1°C in September to a cool 10.1°C in October. Diurnal temperature variations are also pronounced during these seasons, though slightly less so than in summer.

The city of Grand Coulee experiences a climate with very low precipitation throughout the year. There is no pronounced rainy season, but there are periods with slightly more precipitation and months that are practically arid.

The driest months in Grand Coulee are July and August. During this time, there is almost no rain, with an average of 0 mm and only about one day of precipitation in each of these months. June and September are also characterized by very little rainfall (about 1 mm) and a small number of wet days (approximately 4 days).

A relatively "wetter" period occurs in late autumn and winter. January stands out with the highest number of days with precipitation—around 13—followed by December (about 12 days) and November (around 11 days). These months see an average of 2 mm of precipitation each. Given the low average temperatures in January (around -1.5°C) and December (around -1.9°C), precipitation during this time of year likely falls as snow or freezing drizzle. Snowfall is also likely in November when temperatures drop close to freezing. From March to October, any precipitation that does occur is primarily light rain, with 6 to 7 wet days per month, excluding the very dry summer months.

When planning a trip to Grand Coulee, it's important to consider the significant seasonal temperature swings and the nature of the precipitation. In summer (June–August), it is hot and dry: average temperatures stay around 24-25°C, with highs often exceeding 30°C, and there is almost no rain. For this period, light, breathable clothing, shorts, T-shirts, and sandals are ideal. Be sure to bring sunscreen, a hat, and sunglasses. In spring (March–May) and early autumn (September–October), the weather is more variable, with temperatures ranging from cool to moderately warm. During these times, the principle of layering is essential: T-shirts, light sweaters or fleeces, and a windbreaker or light jacket will help you stay comfortable. Comfortable walking shoes are a must any time of year.

The winter months (December–February) and late autumn (November) in Grand Coulee are characterized by cold weather: average temperatures hover around freezing and can drop to -5°C. For this time of year, you'll need a warm winter jacket (preferably wind- and water-resistant), a hat, gloves, and a scarf. Thermal underwear and insulated trousers are also recommended. Although the total amount of precipitation is low (1-2 mm per month), there are days with rain or snow during these seasons (up to 13 days in January), so waterproof footwear will be very useful. During transitional periods like early spring and late autumn, layering will allow you to easily adapt to changing weather conditions throughout the day. A small daypack for outings—to store an extra layer of clothing or a water bottle—will also be very handy.