What are the best and worst months to have a picnic? Wind in northern Colorado makes it complicated
Wind can certainly be an obnoxious weather pattern. Not only can it mess up your hair, blow away your picnic blanket, or make the temperature feel colder than it is, but it also can be dangerous, causing injuries, structural damage, and even death.
The area north of Denver, including Boulder, is known to be fairly windy. In Boulder, the late winter and early spring months are the windiest, with the highest wind speeds of the year reached in April, February, and March at around 8.5 mph each.
While April might have the most consistent high winds of any of the months, the maximum wind speeds per month tell a slightly different story. February, April, and December have the highest maximum wind speeds on average, reaching 21 mph in February.
The gust speeds in Boulder are more intense during the winter. December has the highest average gust speed of any month at 35.9 mph, followed by January and February. December is a month to watch out for for windstorms or even fires–the 2021 Marshall Fire was caused in part by high wind gusts in December. Aside from causing fires, high-speed gusts can contribute to car accidents, power outages, and other disasters.
By comparison, the city of Broomfield, which is 13 miles southeast of Boulder but still north of Denver, has less severe wind speeds overall. April, February, and March are the windiest months in Broomfield, where the average wind speed for each windy month is about 5 mph. While the months with the most overall wind are the same in Boulder and Broomfield, Boulder has wind speeds that are about 3 mph faster on average. In fact, the month with the lowest wind speed in Boulder, September with an average of 6.1 mph, is still higher than Broomfield’s highest month for wind speed.
Similarly, the maximum speeds and gust speeds are lower in Broomfield than they are in Boulder. In Broomfield, the months with the windiest maximum speeds are April, February, and March, with average wind speeds of around 17–18 mph. These averages are also around 3 mph lower than those of Boulder. The gustiest months in Broomfield are January, February, and December, with gust speeds of around 32 mph.
While it might be easy to dismiss Broomfield’s wind speeds since they are consistently lower than Boulder’s, their wind is not insignificant. Wind gusts of 32 mph are still enough to make it difficult to walk. And the highest recorded gusts from 2010 to 2023 in both Boulder and Broomfield are enough to cause serious damage. Broomfield’s highest gusts are nearly 75 mph, which is enough to uproot a tree, while Boulder has reached gust speeds of over 90 mph, which can break a window, overturn a mobile home, or even take a roof off of a house.
What are the least windy months in Boulder and Broomfield, the months best suited to picnics and other outdoor activities? The least windy months in both cities are those of the late summer and early autumn, so October, September, August, and July. October has consistently low average wind, but the gusts can be quite high as colder weather begins, around 30 mph on average. July and August have gusts of around 25–27 mph, and the average wind speed is around 4 mph in Broomfield and 6 mph in Boulder. September has the lowest wind gusts out of any month, as well as the lowest average wind speeds.
September has by far the best picnic weather then, since it is both the least windy month and has more comfortable temperatures than those of July and August. Planning a late-summer picnic avoids both the high winds of the spring and the midsummer heat. However, a September picnic can bring other issues, such as more aggressive wasps, which might require extra planning to repel them.
As we start approaching the windiest months of the year, there are a few things you can do to stay safe. During particularly severe winds, which are sustained wind speeds of 40 mph or higher or gusts of 58 mph or higher, stay indoors and postpone traveling if possible. If driving, reduce speed, watch carefully for any objects being blown onto the road, and pull over if needed. Even if the wind isn’t dangerously fast, dressing appropriately for the temperature (wind chill can make it feel colder) and securing any items outdoors can help you to protect yourself and others.
While it’s disappointing to have to postpone plans, planning a picnic for a calm day in September rather than a windy day in April will most likely make for a better experience. Alternatively, if you’re willing to go on a bit of a drive, find a park in Broomfield, because although it still could be quite windy, the wind will be less likely to ruin your plans!
