Bumpass, Virginia · field elev 351 ft
Density Altitude at Lake Anna (7W4)
Lake Anna sits at 351 ft, and even a typical July afternoon (87 °F) only lifts density altitude to about 2,213 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 | 35.3 | −1,150 ft | 45.2 | −470 ft |
| February | 38.2 | −949 ft | 49.4 | −186 ft |
| March | 45.5 | −449 ft | 58.2 | 399 ft |
| April | 56.1 | 260 ft | 69.8 | 1,152 ft |
| May | 64.0 | 778 ft | 76.0 | 1,546 ft |
| June | 71.9 | 1,286 ft | 83.2 | 1,996 ft |
| July | 76.0 | 1,546 ft | 86.7 | 2,213 ft |
| August | 74.4 | 1,445 ft | 85.3 | 2,126 ft |
| September | 67.6 | 1,011 ft | 79.0 | 1,734 ft |
| October | 56.5 | 287 ft | 68.6 | 1,075 ft |
| November | 45.8 | −429 ft | 57.4 | 346 ft |
| December | 38.1 | −956 ft | 48.1 | −274 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 7W4
DENSITY ALTITUDE
Field elevation 351 ft — the air behaves like 2,231 ft.
- PRESSURE ALT
- 352 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 Virginia fields
- KLKU — Louisa County/Freeman Field
Louisa · elev 494 ft
- KOFP — Hanover County Municipal
Richmond/Ashland · elev 207 ft
- KOMH — Orange County
Orange · elev 464 ft
- KEZF — Shannon
Fredericksburg · elev 85 ft
- KGVE — Gordonsville Municipal
Gordonsville · elev 452 ft
- KRMN — Washington Exec/Stafford Regional
Stafford · elev 219 ft
- KCJR — Culpeper Regional
Culpeper · elev 316 ft
- KRIC — Richmond International
Richmond · elev 168 ft
Frequently asked questions
How high does density altitude get at 7W4 in summer?
On a typical July afternoon — around 87 °F at the nearest NOAA normals station — density altitude at Lake Anna reaches roughly 2,213 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 7W4 on an average day?
It swings with the seasons: from roughly −1,150 ft at the coldest month's average temperature to about 1,546 ft at the warmest month's — all from a constant field elevation of 351 ft. The month-by-month table above carries the full year.
What is the field elevation of Lake Anna?
351 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 7W4 (FAA), in Bumpass, Virginia.