Post Mills, Vermont · field elev 696 ft
Density Altitude at Post Mills (2B9)
Post Mills sits at 696 ft, and even a typical July afternoon (82 °F) only lifts density altitude to about 2,331 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 | 17.7 | −1,968 ft | 28.9 | −1,167 ft |
| February | 19.8 | −1,816 ft | 31.8 | −963 ft |
| March | 29.4 | −1,132 ft | 41.3 | −307 ft |
| April | 42.2 | −245 ft | 55.1 | 621 ft |
| May | 55.0 | 614 ft | 68.1 | 1,467 ft |
| June | 64.3 | 1,222 ft | 76.7 | 2,012 ft |
| July | 69.4 | 1,550 ft | 81.8 | 2,331 ft |
| August | 67.8 | 1,447 ft | 80.6 | 2,256 ft |
| September | 59.8 | 930 ft | 72.9 | 1,772 ft |
| October | 47.1 | 87 ft | 58.7 | 858 ft |
| November | 35.7 | −692 ft | 45.5 | −21 ft |
| December | 25.1 | −1,436 ft | 34.3 | −789 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 2B9
DENSITY ALTITUDE
Field elevation 696 ft — the air behaves like 2,343 ft.
- PRESSURE ALT
- 697 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 Vermont fields
- KMPV — Edward F Knapp State
Barre/Montpelier · elev 1,166 ft
- 0B7 — Warren-Sugarbush
Warren · elev 1,470 ft
- KVSF — Hartness State (Springfield)
Springfield · elev 578 ft
- KRUT — Rutland/Southern Vermont Regional
Rutland · elev 787 ft
- 6B0 — Middlebury State
Middlebury · elev 494 ft
- KMVL — Morrisville-Stowe State
Morrisville · elev 733 ft
- KCDA — Caledonia County
Lyndonville · elev 1,188 ft
- VT8 — Shelburne
Shelburne · elev 325 ft
Frequently asked questions
How high does density altitude get at 2B9 in summer?
On a typical July afternoon — around 82 °F at the nearest NOAA normals station — density altitude at Post Mills reaches roughly 2,331 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 2B9 on an average day?
It swings with the seasons: from roughly −1,968 ft at the coldest month's average temperature to about 1,550 ft at the warmest month's — all from a constant field elevation of 696 ft. The month-by-month table above carries the full year.
What is the field elevation of Post Mills?
696 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 2B9 (FAA), in Post Mills, Vermont.