St Marys, Pennsylvania · field elev 1,934 ft
Density Altitude at St Marys Municipal (KOYM)
St Marys Municipal sits at 1,934 ft, and even a typical July afternoon (79 °F) only lifts density altitude to about 3,638 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 | 21.8 | −119 ft | 30.5 | 492 ft |
| February | 23.4 | −6 ft | 33.3 | 685 ft |
| March | 31.7 | 575 ft | 42.5 | 1,313 ft |
| April | 43.7 | 1,393 ft | 56.4 | 2,234 ft |
| May | 54.7 | 2,123 ft | 67.4 | 2,942 ft |
| June | 62.8 | 2,648 ft | 74.7 | 3,401 ft |
| July | 66.8 | 2,904 ft | 78.5 | 3,638 ft |
| August | 65.5 | 2,821 ft | 77.4 | 3,569 ft |
| September | 59.3 | 2,422 ft | 71.1 | 3,176 ft |
| October | 47.8 | 1,668 ft | 58.7 | 2,384 ft |
| November | 36.8 | 926 ft | 45.6 | 1,521 ft |
| December | 27.1 | 254 ft | 34.5 | 768 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 KOYM
DENSITY ALTITUDE
Field elevation 1,934 ft — the air behaves like 3,668 ft.
- PRESSURE ALT
- 1,935 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 Pennsylvania fields
- KFIG — Clearfield-Lawrence
Clearfield · elev 1,516 ft
- KDUJ — Dubois Regional
Dubois · elev 1,817 ft
- KBFD — Bradford Regional
Bradford · elev 2,143 ft
- 1N3 — Albert
Philipsburg · elev 1,784 ft
- N35 — Punxsutawney Municipal
Punxsutawney · elev 1,445 ft
- KPSB — Mid-State
Philipsburg · elev 1,948 ft
- KAXQ — Clarion County
Clarion · elev 1,458 ft
- N96 — Bellefonte
Bellefonte · elev 1,072 ft
Frequently asked questions
How high does density altitude get at KOYM in summer?
On a typical July afternoon — around 79 °F at the nearest NOAA normals station — density altitude at St Marys Municipal reaches roughly 3,638 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 KOYM on an average day?
It swings with the seasons: from roughly −119 ft at the coldest month's average temperature to about 2,904 ft at the warmest month's — all from a constant field elevation of 1,934 ft. The month-by-month table above carries the full year.
What is the field elevation of St Marys Municipal?
1,934 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is KOYM (ICAO) / OYM (FAA), in St Marys, Pennsylvania.