https://www.boulderweather.com/tags/july-4th/Recent content in July 4th on BoulderWeather.comHugo -- gohugo.ioenBoulderweather.comSat, 13 Jun 2026 00:00:00 +0000https://www.boulderweather.com/post/boulder-july-4th-fire-risk/Sat, 13 Jun 2026 00:00:00 +0000https://www.boulderweather.com/post/boulder-july-4th-fire-risk/ <h2 id="why-boulder-bans-every-backyard-firework--sparklers-included">Why Boulder Bans Every Backyard Firework — Sparklers Included</h2> <p><script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-1012089347386563" crossorigin="anonymous"></script> <ins class="adsbygoogle" style="display:block" data-ad-client="ca-pub-1012089347386563" data-ad-slot="1011306739" data-ad-format="auto" data-full-width-responsive="true"></ins> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> Boulder is the rare Front Range city where a sparkler is as illegal as a mortar shell, and that surprises a lot of new residents. The reason is written into the calendar: the first week of July lands in the hot, dry gap before the summer monsoon arrives, when the grasses that cured out in June are at their most flammable and the afternoon humidity bottoms out. The <a href="https://www.weather.gov/bou/Climate_Record_July">July 4 daily normal high at the Denver/Boulder climate station is 89°F</a>, and the record for the date is 102°F set in 1874 — heat that bakes the last moisture out of foothills grass and ditch-bank weeds. Drop a spark into that on a breezy afternoon and you have the ingredients of a fast grass fire, which is exactly the scenario Boulder's fireworks rules are built to prevent.</p>