| Geyser | 1991-07-21 |
|---|---|
| Echinus | 0830, 0920, 0955, 1110, 1210, 1315 maj, 1512, 1550 |
| Incline | 1200 |
| Steamboat | 1200 |
| Values for Old Faithful Area | 1991-07-21 |
|---|---|
| Astronomical Twilight Begin | 03:46 |
| Nautical Twilight Begin | 04:39 |
| Civil Twilight Begin | 05:23 |
| Sunrise | 05:58 |
| Sunset | 21:01 |
| Civil Twilight End | 21:35 |
| Nautical Twilight End | 22:20 |
| Astronomical Twilight End | 23:13 |
| Moon Illumination | 74.76% |