Petersburg, West Virginia · field elev 963 ft
Density Altitude at Grant County (W99)
Grant County sits at 963 ft, and even a typical July afternoon (89 °F) only lifts density altitude to about 3,068 ft — heat still trims performance, but the field rarely turns high-and-hot.
Typical density altitude by month
| Month | Avg temp °F | DA at avg temp | Afternoon high °F | DA on a typical afternoon |
|---|---|---|---|---|
| January | 33.7 | −498 ft | 44.2 | 223 ft |
| February | 36.2 | −324 ft | 47.2 | 425 ft |
| March | 43.5 | 175 ft | 55.6 | 984 ft |
| April | 54.0 | 878 ft | 67.7 | 1,769 ft |
| May | 62.8 | 1,454 ft | 75.7 | 2,276 ft |
| June | 71.5 | 2,011 ft | 84.4 | 2,817 ft |
| July | 75.7 | 2,276 ft | 88.5 | 3,068 ft |
| August | 73.9 | 2,163 ft | 86.3 | 2,934 ft |
| September | 67.3 | 1,743 ft | 80.6 | 2,582 ft |
| October | 55.4 | 970 ft | 68.6 | 1,827 ft |
| November | 44.8 | 263 ft | 56.6 | 1,049 ft |
| December | 37.1 | −262 ft | 47.4 | 438 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 W99
DENSITY ALTITUDE
Field elevation 963 ft — the air behaves like 3,099 ft.
- PRESSURE ALT
- 964 ft
- ISA DEVIATION
- —
- RULE-OF-THUMB DA
- —
- AIR DENSITY INDEX
- —
- AIR DENSITY
- —
- 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 West Virginia fields
- KEKN — Elkins/Randolph County (Jennings Randolph Field)
Elkins · elev 1,987 ft
- 79D — Philippi/Barbour County Regional
Philippi · elev 1,755 ft
- 70D — Titus Field
Arthurdale · elev 1,863 ft
- W22 — Upshur County Regional
Buckhannon · elev 1,635 ft
- KMGW — Morgantown Municipal/Walter L Bill Hart Field
Morgantown · elev 1,244 ft
- KCKB — North Central West Virginia
Clarksburg · elev 1,224 ft
- 4G7 — Fairmont Municipal-Frankman Field
Fairmont · elev 1,032 ft
- 6W0 — Wade F Maley Field
Shinnston · elev 997 ft
Frequently asked questions
How high does density altitude get at W99 in summer?
On a typical July afternoon — around 89 °F at the nearest NOAA normals station — density altitude at Grant County reaches roughly 3,068 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 W99 on an average day?
It swings with the seasons: from roughly −498 ft at the coldest month's average temperature to about 2,276 ft at the warmest month's — all from a constant field elevation of 963 ft. The month-by-month table above carries the full year.
What is the field elevation of Grant County?
963 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is W99 (FAA), in Petersburg, West Virginia.