Weather in Flagstaff

Planning a trip or simply interested in the weather in Flagstaff? Here you will find the latest information, including forecasts and weather charts, to ensure your holiday or business trip is as comfortable as possible.

The climate of Flagstaff is characterised as continental with four distinct seasons, due to its location and altitude. The city experiences significant temperature fluctuations throughout the year: from cool, sometimes freezing winters to warm summers. Overall, Flagstaff is characterised by relatively low humidity and low precipitation throughout most of the year.

Winters in Flagstaff (from December to February) are quite cold, with average temperatures around 0°C – 2.5°C and night-time minimums dropping significantly below zero. Summer (from June to August), on the contrary, is warm and sunny, with average daytime temperatures in the range of 20°C – 22°C. Notably, July and August see a slight increase in rainfall and the number of rainy days, which can be attributed to summer thunderstorms characteristic of the region.

Spring (March-May) and autumn (September-November) are pleasant transitional seasons. Spring sees gradual warming from a cool March to a moderately warm May. Autumn brings gradual cooling but often delights with clear and comfortable weather. Precipitation during these periods, as in winter, remains low, making Flagstaff attractive to visit at different times of the year, depending on your temperature preferences.

The temperature regime in Flagstaff demonstrates significant annual fluctuations, typical of its high-altitude location. The hottest month is July, when the average temperature is 22.3°C, and daytime maximums often reach 28.7°C. In contrast, the coldest months are traditionally considered January (average temperature 0.6°C, minimum -4.5°C) and February (average temperature 0.9°C, minimum -4.6°C), when night-time temperatures consistently drop below zero.

The summer months, from June to August, bring warmth and sometimes hot weather to Flagstaff. Daytime temperatures during this period fluctuate on average from 26.8°C to 28.7°C, creating comfortable conditions for outdoor activities. However, evenings and nights offer pleasant coolness, with temperatures dropping to 13°C - 16°C. Winter, covering the period from December to February, is characterised as cold. During the day, the thermometer often stays above the zero mark, reaching an average of 5.7°C - 7.4°C, but nights here are truly wintry, with frosts and average minimum temperatures from -2.4°C to -4.6°C.

One of the distinctive features of Flagstaff's climate is the pronounced diurnal temperature range at almost any time of the year. The difference between daytime maximums and night-time minimums can be quite substantial. For example, in April the average maximum temperature is 16.5°C, while the average minimum is only 2.8°C. Similar fluctuations are characteristic of other months; for instance, in June the difference between the daytime heat (up to 27.5°C) and the night-time cool (around 13.0°C) is quite perceptible. This is an important aspect to consider when preparing for a trip, especially when choosing clothes.

Precipitation in Flagstaff is distributed unevenly throughout the year, but the city is generally characterised by relatively low total rainfall. Two main periods can be distinguished: a wetter summer and a predominantly dry remainder of the year, including winter months when precipitation most often falls as snow.

The highest amount of precipitation falls during the summer months. July is the wettest month, with an average of 4 mm of precipitation, and the number of days with precipitation reaching 16. Next comes August with 3 mm of precipitation and 15 rainy days. These summer rains are typically associated with the monsoon season and can take the form of short downpours. Despite the increased frequency, the total amount of moisture remains comparatively small.

During the rest of the year, dry weather prevails in Flagstaff. The driest month is June, when precipitation tends towards zero (0 mm), and there are only about 3 wet days. Late spring (May), autumn (September, October, November) and early spring (April) are also characterised by low precipitation, usually around 1 mm per month, and a small number of days with precipitation (from 3 to 8). In winter, from December to February, an average of 1-2 mm of precipitation falls per month, distributed over 5-8 days. Given that average minimum temperatures in these months drop below zero (from -4.6°C to -2.4°C), this winter precipitation is highly likely to fall as snow. March can also be relatively wet (2 mm precipitation, 11 days), with precipitation occurring as either rain or snow.

When planning a trip to Flagstaff, it is important to consider the significant temperature fluctuations throughout the year and even throughout the day. The key principle when packing your suitcase should be layering. This will allow you to easily adapt to the morning chill, daytime warmth, and evening cooling. Be sure to bring comfortable walking shoes, as the city and its surroundings are perfect for walking. Regardless of the season, do not forget sunscreen and sunglasses – at high altitude, the sun can be very active.

If your trip falls during the warm season, from late spring to early autumn (May-September), your basic wardrobe can consist of light items: t-shirts, shorts, and summer trousers. However, even in summer, especially in June, evenings can be cool, so a light jacket, sweater, or fleece will be very useful. In July and August, when the number of days with precipitation increases, a compact umbrella or a light waterproof windbreaker would not be amiss. The summer months (June-August) are characterised by warm days with an average temperature of 20-22°C, but evenings can be noticeably cooler.

For travelling during the cold season, from late autumn to early spring (November-March), more thorough preparation is required. Winters in Flagstaff are cold, with average temperatures around 0-3°C and night frosts, so warm layered clothing is mandatory: thermal underwear, fleece jackets, a warm sweater, as well as a windproof and waterproof jacket, especially considering that precipitation during this period (1-2 mm per month) often falls as snow. Don't forget a hat, gloves, and a warm scarf. In transitional seasons, such as April and October, the weather can be changeable, so a combination of lighter items with warm layers will be the optimal solution.