AT A GLANCE
- Rafting season: May through September
- Best for big whitewater: May–June (peak runoff, higher flows)
- Best for families: July–August (warm water, balanced flows)
- Best for scenic floating: Late August–September (calmer, less crowded)
- Best overall month: July (warm, reliable, full flow)
- Worst time: October–April (off-season, no commercial trips)
- Book in advance for July and August weekends
When Is the Best Time to Go Whitewater Rafting in Colorado?
Here’s the honest answer: the best time depends on who’s in your raft.
Want the biggest, fastest, most heart-pounding water? Go in May or June.
Want warm days, reasonable rapids, and kids who’ll sleep on the drive home? Go in July or August.
Want the canyon to yourself and a more relaxed float? September is your month.
There’s no bad time to raft the Colorado River through Glenwood Springs — just different experiences depending on when you show up. Here’s the full breakdown.
The Colorado Rafting Season: May Through September
Whitewater Rafting LLC runs trips from May through September. Outside those months, the river is either too cold, too low, or weather conditions make it unsafe for commercial operations.
The season is driven by Colorado’s snowpack cycle:
- Winter brings heavy snowfall to the Rocky Mountains above Glenwood Springs.
- Spring melts that snow, sending runoff into rivers and reservoirs.
- Summer and fall see those flows gradually taper as snowpack depletes.
This cycle is what makes Colorado rafting a seasonal activity — and what determines the character of the river from month to month.
Month-by-Month Breakdown
May: The Rush — High Water, High Energy
May marks the start of the season and often the highest water levels of the year. Snowmelt is peaking, flows are fast, and the Shoshone section comes alive.
What to expect:
- Biggest waves of the season
- Fastest currents
- Cold water (wetsuits are non-negotiable)
- More intense overall experience
Best for: Experienced rafters, thrill-seekers, and adults without young kids who want the rawest version of the river.
Not ideal for: Families with small children and first-timers who are nervous about water.
Weather note: May weather in Glenwood Springs can swing wildly — 75°F and sunny one day, 50°F with afternoon rain the next. Dress in layers and rent the wetsuit.
June: Still Big, Starting to Warm Up
June is the second-highest flow month and a favorite window for serious rafters. Water is still running fast, but temperatures — both air and water — are beginning to climb.
What to expect:
- Strong flows and exciting Class III action
- Warmer than May
- Canyon wildflowers in bloom
- Beginning of summer crowds
Best for: Adults, teens 12+, and experienced family groups.
Pro tip: June weekends book faster than many people expect. Reserve early.
July: The Sweet Spot — Best Month for Most People
If we had to pick one month, it’s July.
Water flows are reliable, temperatures are warm, and the Shoshone section delivers classic Colorado whitewater. Families, first-timers, groups, and experienced rafters all tend to love July.
“The second half of July, first half of August is the best time to go. This is when the water temperature and air temperature are at their nicest.”
— Shawn A., TripAdvisor Review
What to expect:
- Reliable Class III rafting
- Warm air and water temperatures
- Peak season energy
- All trip types operating
Best for: Everyone.
Book ahead: July weekends fill quickly.
August: Peak Summer, Warmer Water
August delivers warm conditions and a river that’s fully in summer mode. Flows are slightly lower than July in most years, creating calmer stretches between rapids.
What to expect:
- Warmest water of the season
- Energetic Class III Shoshone action
- Peak summer tourism in Glenwood Springs
- Busiest booking month
Best for: Families with young children, first-timers, and groups looking for the warmest possible conditions.
“We had an absolutely amazing experience! We brought three families — 12 people total, including six kids ranging in age from 5 to 14 — and every single person had a fantastic time from start to finish.”
— Jennifer Mueth, Google Review
September: Hidden Gem — Quieter, Scenic, Underrated
September is one of the best-kept secrets on the Colorado River.
Crowds thin dramatically after Labor Day. The canyon takes on beautiful fall colors and the water becomes calmer, making it ideal for guests who prioritize scenery.
What to expect:
- Lower flows and calmer rapids
- Spectacular fall scenery
- Smaller crowds
- Cooler temperatures
Best for: Couples, scenic floaters, returning guests, and anyone seeking a quieter experience.
Important: The season typically ends by late September, so book early in the month for the best availability.
What About Water Levels?
The Colorado River near Glenwood Springs is partially dam-controlled, which helps maintain raftable flows throughout much of the season.
This is one reason Whitewater Rafting LLC has operated successfully for more than 50 years.
Water levels change the character of the trip:
- Higher water (May–June): Faster, bigger, more intense
- Moderate water (July–August): Classic Colorado Class III rafting
- Lower water (September): Calmer and more scenic
All levels are safe with a trained guide. They’re simply different versions of the same river.
Quick Decision Guide: Which Month Is Right for You?
| You Want… | Go In… |
|---|---|
| Maximum whitewater intensity | May or June |
| Best overall conditions | July |
| Warm water and family-friendly conditions | July or August |
| Quieter canyon and scenic floating | September |
| Budget-friendly timing | September |
| Guaranteed availability | Weekdays any month |
Tips for Any Month
Book in advance. Summer weekends fill quickly.
Rent a wetsuit in spring and fall. Cold water and cotton clothing are a miserable combination.
Check the weather forecast. Afternoon thunderstorms are common during July and August.
Consider weekdays. They often offer smaller groups and greater availability.
Ready to Book?
👉 Book Half Day Trip
👉 Book Full Day Trip
👉 Short & Mild Trip (Ages 4+)
👉 See All Trip Options
Questions? Call (970) 945-8477 and we’ll help you find the best time for your group.
Related Reading
- Whitewater Rafting Season in Glenwood Springs
- What to Wear Whitewater Rafting
- Comparing Half Day vs. Full Day Trips
Frequently Asked Questions
What is the best month to go whitewater rafting in Colorado?
July is generally considered the best all-around month thanks to warm temperatures, reliable flows, and family-friendly conditions.
When does the whitewater rafting season start in Colorado?
The season typically begins in May and runs through September.
Is June or July better for whitewater rafting in Colorado?
June is best for thrill-seekers seeking higher water. July is best for families, first-timers, and most visitors.
Can you go rafting in Colorado in September?
Yes. September offers smaller crowds, beautiful scenery, and calmer water conditions.
How far in advance should I book a summer rafting trip?
July and August weekends should ideally be booked 1–2 weeks ahead of time.
Is the water warm enough to swim in during summer?
July and August typically offer the warmest water temperatures of the rafting season.
Does rafting in Colorado get canceled for low water?
Rarely. The Colorado River near Glenwood Springs benefits from reservoir management that helps maintain raftable flows throughout the season.
