Weather in Walla Walla

Planning your day in Walla Walla? Check out the most up-to-date weather information, forecasts, and useful charts to ensure nothing disrupts your plans.

The climate in Walla Walla is characterised by four distinct seasons and significant temperature fluctuations throughout the year. Overall, it can be described as semi-arid, with very hot, dry summers and cool, wetter winters. When preparing for your trip, it is worth noting that the weather here depends heavily on the time of year.

The summer months, especially July and August, are the hottest and driest period. The average temperature rises above 25°C, while daytime highs can easily exceed 32°C. Precipitation is virtually non-existent at this time, making summer ideal for those who love sunny and dry weather. Winter, conversely, is cool and damp, with average temperatures around 2-3°C and frequent overnight frosts. Despite a high number of days with precipitation, the volume is low, indicating frequent but light rain or snow.

Spring and autumn are comfortable transitional seasons. Spring sees rapid warming, while in autumn, temperatures gently decline after the summer heat. These periods offer pleasant, moderate weather that is excellent for exploring the city and its surroundings without the extreme temperatures of summer or the chill of winter.

The temperature regime in Walla Walla features a large annual range, from frosty winter nights to sweltering summer days. The hottest months are traditionally July and August, when the average daytime temperature confidently rises above 32°C. In contrast, winter brings coolness: in December and January, average figures hover around 2-3°C, and night-time temperatures often drop below freezing.

Summer in this region is hot and predominantly dry. Sweltering days give way to significantly cooler nights — this is an important feature of the local climate. The daily temperature difference can reach 15 degrees or more, bringing pleasant relief after the daytime heat. Winters here are quite mild but cool. During the day, the thermometer usually stays above 0°C, ranging from 5°C to 7°C, although night frosts are a common occurrence.

The transitional seasons, spring and autumn, offer the most comfortable weather conditions for visiting. In spring, especially in April and May, temperatures gradually rise from 11°C to 17°C, and nature comes alive. In autumn, during September and October, temperatures smoothly decrease from a pleasant 20°C to a moderate 12°C. These periods are ideal for those who wish to avoid the extremes of summer heat and winter cold.

Walla Walla observes marked seasonality in precipitation, with a clear division into a wet winter and a very dry summer. The bulk of annual precipitation falls between November and February, while the summer months are characterised by minimal rainfall. The wettest month in terms of frequency is December, while the driest is July, which often passes without any rain at all.

The wet season peaks in winter. December records the highest number of days with precipitation — on average 14 days, followed by January and February, each with about 13 "wet" days. Considering that average minimum temperatures in these months hover around zero or drop below, precipitation can fall as light rain or snow. However, the total amount of precipitation is low, indicating a prevalence of lingering drizzle or light snowfall rather than heavy downpours.

Summer in Walla Walla, by contrast, is very arid. July is an absolutely dry month, when on average not a drop of precipitation falls and there are no rainy days. August and September are also distinguished by minimal precipitation and a small number of rainy days (2 and 4 days respectively). This dry and sunny period is perfect for outdoor activities. Spring and autumn are transitional seasons when rainfall gradually decreases towards summer and increases again towards winter.

To ensure your trip to Walla Walla is as comfortable as possible, pay close attention to your choice of clothing, as the weather here has clearly defined seasons. Summer, from June to August, is very hot and dry. Your suitcase must include light, breathable fabrics such as cotton and linen, as well as shorts, t-shirts, and sundresses. Sunscreen with high SPF, a hat, and sunglasses are not just a recommendation, but a necessity. For evening walks, bring a light cardigan or windbreaker, as it can get cooler after sunset.

Winter (December-February) and the shoulder seasons require a more substantial approach. In winter, temperatures stay around freezing, and although precipitation is low, the number of damp and overcast days is significant. The best solution is the layering principle: thermal underwear, a warm sweater or fleece, and waterproof outerwear. A hat, gloves, and a scarf will also be indispensable. In spring and autumn, the weather is changeable, so layering will come to the rescue again. And, of course, at any time of year, you will need comfortable walking shoes, and for the cool and wet months, it is better to choose a waterproof model.