In August, the Wind River Range area has an average nighttime minimum of about 5 C. That temperature requires at least an R 4 sleeping pad, with R 5 or higher for a stronger insulation margin.
Practical meaning: R 4 is the minimum target for about 5 C nights. R 5.8 to R 6.9 is more than the minimum and helps keep the sleeper warmer from below.
Comparison Table
| Pad | Weight | R-value | Packed size | Approx. packed volume | Overall | Product link |
|---|---|---|---|---|---|---|
| Exped Ultra 6.5 M Mummy | 360 g | 6.9 | 21 x 10.5 cm | About 1.8 L | Warmest and lightest. About 1.8 L, or 2.8% of a 65 L backpack. Best insulation-to-weight result, with less rectangular area than broader pads. |  View product |
| MEC Bravo 6 | 455 g | 5.8 | 21 x 8.5 cm | About 1.2 L | Most packable. About 1.2 L, or 1.8% of a 65 L backpack. Useful when food and insulation already take significant pack space. |  View product |
| Big Agnes Rapide SL Insulated | 510 g regular | 4.8 | 20 x 10 cm regular | About 1.6 L | About 1.6 L, or 2.5% of a 65 L backpack. More cushion than the lighter options, with lower insulation than the Exped and MEC pads. |  View product |
| Sea to Summit Ether Light XR Insulated Rectangular | 605 g regular | 4.1 | 24 x 12 cm regular | About 2.7 L | About 2.7 L, or 4.2% of a 65 L backpack. Largest packed volume in this group, but the rectangular shape gives a more consistent sleeping surface. |  View product |
Buying Guide
How the Top Choice Is Selected
| Decision factor | Wind River requirement | Best match | Result |
|---|---|---|---|
| R-value | At least R 4 for about 5 C nights | Exped Ultra 6.5 M Mummy: R 6.9 | Large cold-ground margin |
| Weight | Low carried weight for high-country backpacking | Exped Ultra 6.5 M Mummy: 360 g | Lightest pad in the comparison |
| Compactability | Small enough for a 65 L pack with food and insulation | Exped Ultra 6.5 M Mummy: about 1.8 L, or 2.8% of a 65 L backpack | Compact enough without giving up insulation |
| Top choice | Exped Ultra 6.5 M Mummy. It best combines the required R-value, the lowest weight, and compact packed volume for Wind River Range in August. | ||
Other pads fit other priorities: MEC Bravo 6 for lowest packed volume, Big Agnes Rapide SL for cushion, and Sea to Summit Ether Light XR for a rectangular sleeping surface.
Match R-value
Use the coldest expected ground conditions, not the afternoon high.
Check volume
A 2 to 3 L pad is noticeable inside a 65 L pack.
Choose shape
Mummy saves weight; rectangular gives more usable area.
Verify listing
Use the product link because prices and availability change.
Recommendation for Wind River Range in August
Top choice: Exped Ultra 6.5 M Mummy. The August nighttime minimum is about 5 C, which requires at least R 4. At 360 g with an R-value of 6.9 and a packed size of 21 x 10.5 cm, the Exped gives the strongest insulation-to-weight result in this comparison while using about 2.8% of a 65 L backpack.
The MEC Bravo 6 is the second choice for this location. It adds 95 g compared with the Exped and has a lower R-value of 5.8, but its smaller calculated packed volume makes it a strong option when pack space is limited.
Specification limit: Minimum trail weight is not specified in the product listings used for these pads. We therefore compare listed product weight, R-value, thickness, packed dimensions, and listed price only.
Related Guides
Use these guides with this sleeping pad comparison when planning the rest of the sleep and shelter system.
- Choosing a Sleeping Bag for Backpacking
- 2-Person Backpacking Tent Comparison
- How Gear Recommendations Are Made
FAQ
What R-value is appropriate for the Wind River Range in August?
The Wind River Range area has an average August nighttime minimum of about 5 C. That temperature requires at least R 4, with R 5 or higher for a stronger cold-ground margin.
Which sleeping pad is the top choice for Wind River Range in August?
Exped Ultra 6.5 M Mummy is the top choice in this comparison because it combines 360 g weight, R 6.9 insulation, and a 21 x 10.5 cm packed size.
Why are product images linked in this guide?
Each recommended product image links to the product page so readers can inspect the current retailer listing.
How We Help
We help backpackers match sleeping pads to destination, season, expected night temperatures, pack capacity, and the rest of the sleep system. A warm sleeping bag can still feel cold if the pad does not insulate well enough from the ground.
Use the planner to plan your next backpacking trip and build a gear list based on your route, season, trip length, and expected conditions.
References
- NOAA NCEI GHCN Daily climate data for the Wind River Range area.
- U.S. Forest Service, Bridger-Teton National Forest.
- MEC, Exped Ultra 6.5 M Mummy Sleep Pad listing.
- MEC, MEC Bravo 6 Sleeping Pad listing.
- Big Agnes, Rapide SL Insulated product page.
- MEC, Big Agnes Rapide SL Insulated listing.
- MEC, Sea to Summit Ether Light XR Insulated Rectangular listing.
Plan your next backpacking trip with the planner.