Weather in Santa Rosa

Planning your day in Santa Rosa? Here you will find the most up-to-date weather information, including detailed forecasts and visual charts.

The climate in Santa Rosa, USA, can be described as Mediterranean, with distinctly defined seasons. The city enjoys warm, and at times hot, dry summers and mild, wetter winters. Such a climate makes Santa Rosa attractive to visit almost all year round, although the character of the weather changes significantly depending on the season.

The summer months, especially from June to August, are distinguished by a large number of sunny days and minimal rainfall. The average temperature during this period hovers around 21-22°C, while maximum values can reach 30°C. Winter, from December to February, brings cooler weather with average temperatures around 10°C and increased precipitation, though frosts occur rarely. Spring and autumn are transitional seasons with comfortable temperatures and moderate rainfall, gradually decreasing towards summer and increasing towards winter.

One of the notable features of the weather in Santa Rosa is the pronounced dry season in summer, when rain is practically absent, and the wetter period from November to March. This creates contrasting conditions for vegetation and active recreation. Travellers should take these seasonal changes into account when planning a trip, especially if outdoor activities are on the agenda.

The weather in Santa Rosa is characterised by noticeable seasonal temperature changes, offering comfortable conditions for visiting at different times of the year. The annual range of average temperatures fluctuates from a cool 9.8°C in December to a warm 22.4°C in July and August, which are the hottest months. The coldest months are traditionally considered to be December, January, and February, with average temperatures around 10°C.

The summer months in Santa Rosa, especially June, July, and August, bring real warmth. The average daily temperature in July and August reaches 22.4°C, while maximum values can rise to 30.1°C in July. A characteristic feature of the summer period is significant daily temperature fluctuations: nights remain pleasantly cool (around 14-15°C), while hot weather sets in during the day. This creates comfortable conditions for evening walks after a hot day. Precipitation is practically absent during the summer months.

Winter in Santa Rosa is quite mild and cool. Average temperatures in December, January, and February hold around 10°C. Minimum night-time temperatures drop on average to 4.5°C - 5.7°C, and daytime highs usually do not exceed 14-16°C. Although frosts are not a typical phenomenon, nights can be quite fresh. Daily temperature fluctuations in winter are less pronounced than in summer but are still noticeable, averaging 9-11°C. The winter months are also characterised by the highest amount of rainfall.

Santa Rosa observes a pronounced seasonality in precipitation, with a clear division into wet and dry periods throughout the year. The winter months bring the main share of annual moisture, while summer is characterised by an almost complete absence of rain.

The wettest period in Santa Rosa is the interval from November to March. In these months, the amount of precipitation reaches its maximum, amounting to about 4 mm in January, February, March, and December. The rainiest month by the number of days with precipitation often turns out to be March, when it rains on average for 13 days. Significant numbers of wet days are also observed in January and December – about 11. November, with 3 mm of precipitation and 7 rainy days, also contributes to this wet season. Given the temperature regime, precipitation falls predominantly in the form of rain.

The summer months – June, July, and August – are absolutely dry, with zero precipitation and an absence of rainy days. September also remains very dry, with a minimal chance of precipitation (on average 1 wet day and 0 mm of rainfall). Transitional months, such as April, May, and October, are characterised by a small amount of precipitation (about 1 mm) and a low number of rainy days (from 2 to 4), which indicates a gradual transition from the wet season to the dry one and back.

When planning a trip to Santa Rosa, it is important to consider the pronounced seasonality of the weather. The climate here is characterised by mild, rather wet winters and warm, dry summers. Regardless of the time of year, comfortable walking shoes will become your best companion, as the city and its surroundings are conducive to walking. The principle of layering in clothing is the key to comfort, as daytime and evening temperatures can differ noticeably, especially in the transitional seasons.

In the summer months, from June to September, when the average temperature holds around 21-22°C, and the maximum can reach 28-30°C, and precipitation is practically absent (0 mm), your wardrobe should consist of light, breathable clothing: t-shirts, shorts, sundresses. Be sure to take sunscreen, a hat, and sunglasses for protection from the bright sun. Even in summer, a light cardigan or sweater may come in handy in the evening, as the temperature can drop to 14-15°C.

In winter, from December to March, the weather in Santa Rosa is cooler and wetter, with average temperatures around 10-11°C (minimums can drop to 5°C) and more frequent rainfall (up to 4 mm and 11-13 rainy days in January, March, and December). At this time, you will need warm clothes: sweaters, fleece tops, a mid-season jacket (preferably waterproof or at least water-repellent), and possibly an umbrella. In the off-season (April-May and October-November), the weather is changeable: days can already be or still be quite warm (up to 20-25°C in May and October), while evenings are cool. Therefore, pack clothes that can be easily combined: t-shirts, light jumpers, and a windbreaker or light jacket.