| Geyser | 1971-01-31 |
|---|---|
| Castle | 1310 |
| Grand | 1545 |
| Old Faithful | 1118 short, 1217 long, 1332 short, 1420 long, 1538 short, 1630 long |
| Values for Old Faithful Area | 1971-01-31 |
|---|---|
| Astronomical Twilight Begin | 06:03 |
| Nautical Twilight Begin | 06:37 |
| Civil Twilight Begin | 07:12 |
| Sunrise | 07:43 |
| Sunset | 17:30 |
| Civil Twilight End | 18:01 |
| Nautical Twilight End | 18:36 |
| Astronomical Twilight End | 19:10 |
| Moon Illumination | 24.9% |