Bigfork, Montana · field elev 3,072 ft
Density Altitude at Ferndale Airfield (53U)
From a field elevation of 3,072 ft, a typical July afternoon at Ferndale Airfield (82 °F) raises density altitude to about 5,227 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 | 24.3 | 1,480 ft | 30.7 | 1,924 ft |
| February | 27.0 | 1,668 ft | 36.1 | 2,292 ft |
| March | 35.4 | 2,245 ft | 45.2 | 2,903 ft |
| April | 42.7 | 2,736 ft | 54.1 | 3,487 ft |
| May | 51.2 | 3,298 ft | 64.2 | 4,134 ft |
| June | 57.6 | 3,713 ft | 70.7 | 4,543 ft |
| July | 64.7 | 4,166 ft | 81.8 | 5,227 ft ▲ |
| August | 63.8 | 4,109 ft | 81.7 | 5,221 ft ▲ |
| September | 54.5 | 3,513 ft | 70.1 | 4,505 ft |
| October | 43.4 | 2,783 ft | 54.8 | 3,532 ft |
| November | 32.2 | 2,027 ft | 38.9 | 2,482 ft |
| December | 25.3 | 1,550 ft | 30.4 | 1,903 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 53U
DENSITY ALTITUDE caution
Field elevation 3,072 ft — the air behaves like 5,239 ft.
- PRESSURE ALT
- 3,074 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 Montana fields
- S27 — Kalispell City
Kalispell · elev 2,932 ft
- KGPI — Glacier Park International
Kalispell · elev 2,977 ft
- 8U4 — Spotted Bear /Usfs/
Spotted Bear · elev 3,672 ft
- 8S1 — Polson
Polson · elev 2,941 ft
- 58S — Whitefish
Whitefish · elev 3,066 ft
- 0S1 — Meadow Creek Usfs
Meadow Creek · elev 3,993 ft
- 7S0 — Ronan
Ronan · elev 3,086 ft
- 8U2 — Schafer /Usfs/
Schafer · elev 4,856 ft
Frequently asked questions
How high does density altitude get at 53U in summer?
On a typical July afternoon — around 82 °F at the nearest NOAA normals station — density altitude at Ferndale Airfield reaches roughly 5,227 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 53U on an average day?
It swings with the seasons: from roughly 1,480 ft at the coldest month's average temperature to about 4,166 ft at the warmest month's — all from a constant field elevation of 3,072 ft. The month-by-month table above carries the full year.
What is the field elevation of Ferndale Airfield?
3,072 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 53U (FAA), in Bigfork, Montana.