Buffalo, Wyoming · field elev 4,970 ft
Density Altitude at Johnson County (KBYG)
From a field elevation of 4,970 ft, a typical July afternoon at Johnson County (85 °F) raises density altitude to about 7,711 ft — solidly into the range where performance charts deserve a close read.
Typical density altitude by month
| Month | Avg temp °F | DA at avg temp | Afternoon high °F | DA on a typical afternoon |
|---|---|---|---|---|
| January | 27.5 | 4,066 ft | 37.5 | 4,739 ft |
| February | 27.3 | 4,052 ft | 37.0 | 4,706 ft |
| March | 35.9 | 4,633 ft | 46.4 | 5,324 ft ▲ |
| April | 42.9 | 5,096 ft | 53.4 | 5,776 ft ▲ |
| May | 52.0 | 5,686 ft | 62.8 | 6,370 ft ▲ |
| June | 61.9 | 6,314 ft | 74.0 | 7,061 ft ▲ |
| July | 71.3 | 6,896 ft | 84.8 | 7,711 ft ▲ |
| August | 69.9 | 6,810 ft | 83.2 | 7,616 ft ▲ |
| September | 59.8 | 6,182 ft | 72.3 | 6,957 ft ▲ |
| October | 46.2 | 5,311 ft | 57.2 | 6,018 ft ▲ |
| November | 35.0 | 4,573 ft | 45.3 | 5,253 ft ▲ |
| December | 27.0 | 4,032 ft | 36.8 | 4,693 ft |
▲ above 5,000 ft · ⚠ above 8,000 ft. These are planning references at standard pressure and dry air — afternoon humidity and low pressure both push the real number higher. Run today's values below.
Run today’s numbers for KBYG
DENSITY ALTITUDE caution
Field elevation 4,970 ft — the air behaves like 7,723 ft.
- PRESSURE ALT
- 4,972 ft
- ISA DEVIATION
- —
- RULE-OF-THUMB DA
- —
- AIR DENSITY INDEX
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- AIR DENSITY
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- WATER · GRAINS/LB
- —
For training and reference · verify with official sources and your POH before flight · no tool on this site renders a go / no-go judgment
Nearby Wyoming fields
- KSHR — Sheridan County
Sheridan · elev 4,021 ft
- KGCC — Northeast Wyoming Regional
Gillette · elev 4,365 ft
- KWRL — Worland Municipal
Worland · elev 4,252 ft
- KGEY — South Big Horn County
Greybull · elev 3,942 ft
- U68 — North Big Horn County
Cowley/Lovell/Byron · elev 4,094 ft
- KHSG — Hot Springs County
Thermopolis · elev 4,892 ft
- KHAD — Irwins Sky Ranch
Casper · elev 5,370 ft
- KCPR — Casper/Natrona County International
Casper · elev 5,344 ft
Frequently asked questions
How high does density altitude get at KBYG in summer?
On a typical July afternoon — around 85 °F at the nearest NOAA normals station — density altitude at Johnson County reaches roughly 7,711 ft at standard pressure. Hotter-than-normal days, low pressure, and humidity all push it higher, so run the day's actual numbers before flying.
What is the density altitude at KBYG on an average day?
It swings with the seasons: from roughly 4,032 ft at the coldest month's average temperature to about 6,896 ft at the warmest month's — all from a constant field elevation of 4,970 ft. The month-by-month table above carries the full year.
What is the field elevation of Johnson County?
4,970 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KBYG (ICAO) / BYG (FAA), in Buffalo, Wyoming.