Valdez, Alaska · field elev 2,080 ft
Density Altitude at Thompson Pass (K55)
Thompson Pass sits at 2,080 ft, and even a typical July afternoon (70 °F) only lifts density altitude to about 3,260 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 | −2.3 | −1,701 ft | 4.9 | −1,162 ft |
| February | 6.0 | −1,080 ft | 17.1 | −272 ft |
| March | 14.0 | −495 ft | 29.0 | 569 ft |
| April | 31.6 | 750 ft | 44.5 | 1,628 ft |
| May | 43.9 | 1,588 ft | 57.3 | 2,473 ft |
| June | 53.2 | 2,205 ft | 66.6 | 3,070 ft |
| July | 57.1 | 2,460 ft | 69.6 | 3,260 ft |
| August | 52.4 | 2,152 ft | 64.8 | 2,955 ft |
| September | 42.3 | 1,480 ft | 53.6 | 2,231 ft |
| October | 26.5 | 395 ft | 35.7 | 1,032 ft |
| November | 7.4 | −977 ft | 14.6 | −452 ft |
| December | −0.5 | −1,565 ft | 6.6 | −1,036 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 K55
DENSITY ALTITUDE
Field elevation 2,080 ft — the air behaves like 3,285 ft.
- PRESSURE ALT
- 2,081 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 Alaska fields
- PAVD — Valdez Pioneer Field
Valdez · elev 128 ft
- PAKA — Tatitlek
Tatitlek · elev 62 ft
- CKU — Cordova Municipal
Cordova · elev 59 ft
- PACV — Merle K (Mudhole) Smith
Cordova · elev 53 ft
- PAAX — Chitina
Chitina · elev 556 ft
- Z93 — Copper Center 2
Copper Center · elev 1,150 ft
- Z14 — Tazlina
Tazlina · elev 2,450 ft
- PAGK — Gulkana
Gulkana · elev 1,586 ft
Frequently asked questions
How high does density altitude get at K55 in summer?
On a typical July afternoon — around 70 °F at the nearest NOAA normals station — density altitude at Thompson Pass reaches roughly 3,260 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 K55 on an average day?
It swings with the seasons: from roughly −1,701 ft at the coldest month's average temperature to about 2,460 ft at the warmest month's — all from a constant field elevation of 2,080 ft. The month-by-month table above carries the full year.
What is the field elevation of Thompson Pass?
2,080 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is K55 (FAA), in Valdez, Alaska.