STATISTICS / HEAT
Death Valley tops 110°F about 93 days a year
Furnace Creek averaged 92.6 days at or above 110°F in 2021–2025, up from 86.8 in the 1990s, with a record 122 in 2012. Phantom Ranch in the inner Grand Canyon nearly doubled from 13.1 in the 2010s to 25.6 in 2021–2025. Zion rarely tops 110°F: 2.8 days a year recently, with a record of 8 in 2021.
Updated . NOAA data downloaded October 2026. NPS guidance pages read October 2026.
Main numbers
- 92.6 days a yearDeath Valley (Furnace Creek) averaged 92.6 days at or above 110°F in 2021–2025, against 86.8 in the 1990s. Record: 122 days in 2012.
- 25.6 days, nearly doublePhantom Ranch averaged 25.6 days in 2021–2025, against 13.1 in the 2010s. Record: 39 days in 2020.
- 2.8 days a yearZion averaged 2.8 days in 2021–2025, against 0.4 in the 1990s. Record: 8 days in 2021.
- Warnings, not closuresThe parks manage heat with guidance: Death Valley says do not hike after 10am; Grand Canyon says avoid the inner canyon 10am–4pm and stay out during excessive heat warnings.
110°F days per year by decade
Each bar is the yearly average within the decade. Phantom Ranch (GRCA) station missed the summer of 2008, so that year is excluded from its 2000s average.
110°F days by year, 2015–2025
Death Valley's low year in 2023 (69 days) shows how much one summer can vary. Phantom Ranch set its record 39 in 2020.
Download the data as CSV (all years since 1991).
| Station | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Death Valley | 97 | 99 | 99 | 103 | 91 | 109 | 97 | 95 | 69 | 111 | 91 |
| Grand Canyon | 11 | 20 | 19 | 13 | 0 | 39 | 24 | 18 | 23 | 34 | 29 |
| Zion | 1 | 2 | 7 | 0 | 0 | 6 | 8 | 0 | 3 | 3 | 0 |
Heat closures and alerts
None of the three parks closes for heat on a schedule. Instead each publishes standing heat guidance, escalates to warnings in heat waves, and rescues hikers who misjudge the day. No heat alert was active at any of the three parks when this page was updated (October, off-season).
- Death Valley. Do not hike after 10am at low elevations; stay within a short walk of an air-conditioned vehicle; drink water and eat salty snacks. In July 2024 a motorcyclist died of heat exposure near Badwater Basin and several others were treated (NPS).
- Grand Canyon. Avoid the inner canyon 10am–4pm in summer; the park recommends not hiking below the rim at all during excessive heat warnings. Daytime inner-canyon temperatures can exceed 110°F.
- Zion. Heat illness is one of the park's most common summer emergencies; the park's safety guidance centers on water, salt, shade, and turning back.
Methodology
- Temperatures: NOAA Global Historical Climatology Network Daily (GHCN-Daily), maximum temperature (TMAX) at Furnace Creek USC00042319, Phantom Ranch USC00026471, and Zion USC00429717, downloaded October 2026.
- A "110°F day" is TMAX at or above 43.3°C (433 tenths), the GHCN encoding of a 110°F thermometer reading. US stations report whole degrees Fahrenheit, so exact-110°F days encode as 433.
- Averages skip years with fewer than 300 observed days. Only Phantom Ranch 2008 qualifies (summer missing); its 2025 count of 29 may slightly undercount September, which reported 11 of 30 days.
- Records quoted are station records over each station's full GHCN history, not just 1991–2025.
- Heat guidance and the July 2024 fatality come from the linked NPS pages and news release. Alert status is the NPS API snapshot for October 2026.
Sources
- NOAA GHCN-Daily documentation. Station histories via the per-station CSV access.
- NPS, Death Valley July 2024 fatality. Motorcyclist heat death near Badwater Basin (7 July 2024).
- NPS, Grand Canyon Hike Smart. Inner-canyon heat guidance.
- NPS, Grand Canyon excessive heat warning. Recommendation not to hike below the rim.
- NPS, Zion safety. Heat illness guidance.
Cite this page
np.guide. "110-degree days at Death Valley, Grand Canyon, and Zion." Updated 26 October 2026. https://np.guide/statistics/heat-and-closures
Quotable summaries
Death Valley averages 93 days at or above 110°F a year, with a record 122 in 2012.
Phantom Ranch in the Grand Canyon nearly doubled from 13 days over 110°F a year in the 2010s to 26 in 2021–2025.
Zion rarely tops 110°F: about 3 days a year recently, with a record of 8 in 2021.
The parks manage extreme heat with warnings, not scheduled closures.