Plainville, Connecticut · field elev 202 ft
Density Altitude at Robertson Field (4B8)
Robertson Field sits at 202 ft, and even a typical July afternoon (84 °F) only lifts density altitude to about 1,864 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 | 27.9 | −1,856 ft | 37.0 | −1,218 ft |
| February | 29.7 | −1,729 ft | 39.1 | −1,073 ft |
| March | 37.8 | −1,162 ft | 47.5 | −499 ft |
| April | 48.8 | −411 ft | 59.9 | 327 ft |
| May | 59.1 | 274 ft | 70.4 | 1,007 ft |
| June | 67.9 | 847 ft | 78.7 | 1,533 ft |
| July | 73.3 | 1,192 ft | 84.0 | 1,864 ft |
| August | 71.7 | 1,090 ft | 82.4 | 1,765 ft |
| September | 64.5 | 627 ft | 75.4 | 1,325 ft |
| October | 52.7 | −150 ft | 63.6 | 568 ft |
| November | 42.0 | −873 ft | 52.0 | −196 ft |
| December | 33.1 | −1,490 ft | 41.7 | −894 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 4B8
DENSITY ALTITUDE
Field elevation 202 ft — the air behaves like 1,864 ft.
- PRESSURE ALT
- 203 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 Connecticut fields
- N41 — Mount Tobe
Waterbury · elev 850 ft
- KHFD — Hartford-Brainard
Hartford · elev 18 ft
- KMMK — Meriden Markham Municipal
Meriden · elev 103 ft
- 4B9 — Simsbury
Simsbury · elev 195 ft
- KBDL — Bradley International
Windsor Locks · elev 173 ft
- KOXC — Waterbury-Oxford
Oxford · elev 730 ft
- 7B6 — Skylark Airpark
Warehouse Point · elev 120 ft
- 9B8 — Salmon River Airfield
Marlborough · elev 540 ft
Frequently asked questions
How high does density altitude get at 4B8 in summer?
On a typical July afternoon — around 84 °F at the nearest NOAA normals station — density altitude at Robertson Field reaches roughly 1,864 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 4B8 on an average day?
It swings with the seasons: from roughly −1,856 ft at the coldest month's average temperature to about 1,192 ft at the warmest month's — all from a constant field elevation of 202 ft. The month-by-month table above carries the full year.
What is the field elevation of Robertson Field?
202 ft MSL, from the FAA NASR airport record (28-day cycle effective 2026-08-06). The identifier is 4B8 (FAA), in Plainville, Connecticut.