Category: Climatology (Page 4 of 69)

These posts contain information about the long-term weather patterns of Boulder County. Potential topics may include 30-day weather outlooks, El Nino/La Nina, and seasonal forecasts. You will find less about the day-to-day weather, with more focus on longer trends and patterns.

This Week in Colorado Weather: January 12, 2026

January 12, 2026 / Ben Castellani

A stubborn weather pattern is settling in this week, and Colorado finds itself right in the middle of the action—or the lack of it. While the coasts deal with weather extremes, the Front Range gets a quieter blend of mild spells, a couple of cold fronts, and just enough uncertainty to keep things interesting. Read on for our full outlook of the next seven days to see if this translates into meaningful moisture or just more dry January days.

Winter Storm Recap: 2026’s first snowfall is over and it won’t stick around long

January 9, 2026 / Ben Castellani

A tandem of low pressure systems — one warm and moisture‑rich, the other colder and more dynamic — teamed up just enough to deliver a surprisingly efficient burst of snowfall across the Front Range to end the week. We break down how this two‑part event unfolded, why the timing mattered so much, and where our forecast over‑ and under‑performed. Continue reading

2025 in Review: Boulder’s Wildest Weather Moments of the Year Explored Through 100 Charts & Visuals

January 7, 2026 / BoulderCAST Team

2025 was one of those years where Boulder’s weather never seemed content with a single storyline. We opened with a bitter Arctic punch that delivered our coldest January in nearly two decades, only to swing into a summer packed with 90°+ heat, smoky afternoons, and the hottest day since 2012. The monsoon showed up often but rarely with much enthusiasm, fall dried out in a hurry, and our first snow didn’t arrive until November 29th — the latest on record by a country mile. Now that the dust (and smoke, and snow) has settled, we’ve pulled together a full graphical recap of the temperature swings, precipitation quirks, record‑setting moments, and long‑term trends that defined Boulder’s and Colorado’s atmosphere in 2025. If you want the full story behind the chaos — and a clearer picture of where 2025 truly landed — this is a fun one to dive into. Be warned, there really are 100 charts and visuals to explore. Enjoy!

Why Boulder’s official weather station has moved so much over the last 130 years—and why it matters today

January 6, 2026 / BoulderCAST Team

Boulder’s “official” climate record has never lived in one place for long. Over the past 130 years, the instruments that track our temperature, precipitation, and snowfall have been relocated again and again—sometimes only a few blocks, other times miles away into landscapes with completely different quirks and microclimates. Each move left its own imprint on the long‑term dataset we use today, subtly shaping how we compare modern conditions with the Boulder of decades past.

This Week in Colorado Weather: January 5, 2025

January 5, 2026 / Andy

Warm, gusty weather is kicking off the first full week of 2026, but the atmosphere has a few twists lined up as we move toward the weekend. A stubborn ridge will keep us mild early on as downslope winds ramp up fire concerns. However, a developing trough later in the week will turn us much colder — with even the possibility of snow for Boulder and Denver if the storm track cooperates. The details are still evolving, but there’s plenty to watch in the days ahead.

This Week in Colorado Weather: December 29, 2025

December 29, 2025 / Ben Castellani

After a quick burst of weekend snow and our coldest temperatures since early December, the week ahead turns much quieter across Colorado. Temperatures will climb steadily as Boulder and Denver stay dry into the New Year, while the Mountains prepare for a well‑timed round of snow for the holiday weekend. We’ll walk you through the day‑to‑day weather this week, where the snow will fall, and check in on long‑range guidance which still isn’t advertising much in the way of winter for eastern Colorado.

Winter Weather Update: Snow chances have fizzled, but a sharp cold front will still pack a wintry punch Saturday night

December 27, 2025 / Ben Castellani

After a stretch of December warmth so extreme it rewrote some record books across the Front Range, we’re finally staring down a pattern shift—though not quite the snowy one we initially hoped for. A pair of cold fronts will bring a sharp temperature drop, a few chances for rain and snow, and at least the feeling of winter back to Boulder and Denver. The details have changed quite a bit in the last 24 to 48 hours, but we’ll walk you through what’s still on the table, what’s no longer likely, and where a few surprises could still sneak in Saturday night.

Why is Christmas Day one of the whitest days of the year in Boulder?

December 25, 2025 / BoulderCAST Team

This Christmas will be a scorcher across the Front Range with temperatures soaring towards record highs near 70 degrees, but snow is often part of the equation here on Christmas, whether falling or on the ground. We take a broader look at White Christmas occurrences in Boulder’s historical record and discuss why Christmas Day, out of all days, has one of the highest probabilities of snow on the ground here.