Day Sky Update October 2026
This is the Saint Louis Science Center’s DAY SKY UPDATE for the Month of October 2026.
Information updated monthly or as needed.
Times given as local St. Louis time which is Central Daylight Time (CDT). For definitions of terminology used in the night sky update, click the highlighted text. If relying on times posted in Universal Time (UT), St. Louis is -5 hours when CDT. Additionally, times will be posted in a 24-hour format.
Join us for our next solar telescope viewing each month on the third Sunday, held in association with the St. Louis Astronomical Society. These viewing sessions are weather dependent. For details, see the information at the bottom of this page or visit https://www.slsc.org/explore/mcdonnell-planetarium/public-telescope-viewings/
Daytime Astronomy Primer
Image shows daytime telescope view of the five naked eye planets. Image credit: Eric Gustafson
For most, astronomy is a hobby that is left to the darkness of night. While most astronomical objects are only visible at night, the day sky can offer a careful observer several astronomical targets along with a multitude of atmospheric phenomena to enjoy. When posted, the DAY SKY UPDATE will explore these possibilities which may include a highlight of the month, cloud observing, sun rise/set times, daytime Moon information, daytime planets and other topics. As always, when viewing during daytime, you must use caution as the Sun is always near.
Aside from solar filters, there are other safety steps that you should consider. Sunscreen, hats and sunglasses are always advisable. Visible light is how we observe the world around us, however, there is light we cannot see such as ultraviolet (UV) and infrared (IR) lights. While both are an issue if you are using an optical system, UV light is an issue through exposure. This can be mitigated by using sunscreen, sunglasses and limiting exposed skin. While sunglasses are not safe instruments to view the Sun with, they do protect your eyes from exposure to ultraviolet light that we are susceptible to during the day.
Cloud of the Month
Have you ever seen a cloud that looks like it has precipitation falling but you notice it does not fully reach the ground? Well, that is a cloud feature known as virga. It looks like wispy little clouds falling from a cloud base.
They most frequently form from altocumulus, altostratus, and cumulus clouds. What happens is that the precipitation falls into a layer below the cloud base that is warm and dry. This causes the precipitation to evaporate midair.
What’s fun and interesting is that radar can still detect virga, even though the precipitation does not reach the ground. That’s because the radar beam contacted the precipitation as it was still falling. This can make people think there is rain outside when looking at radar. Going outside to find the ground is still dry can be a bit confusing!
The Sun and the Moon
Sun Information
The month of October sees the Sun decreasing its altitude each day as it continues towards the December Solstice. When viewed from St. Louis, the Sun’s maximum altitude will shift from 48.0° on October 1, 2026, to 37.1° on October 31, 2026. The next major position of the Sun occurs on December 21, 2026, as the Sun reaches the December solstice. This day sees the beginning of winter in the northern hemisphere and summer in the southern hemisphere.
Fall temperatures seem to be here to stay this month with a few warmups likely. If you are looking forward to fall colors, October seems to be the peak month this year for Missouri. By November, most of the US is expected to be past its peak fall colors.
| Dec. Solstice | Dec. 21, 2026 |
| March Equinox | March 20, 2027 |
| June Solstice | June 21, 2027 |
| Sept. Equinox | Sept. 23, 2027 |
Sunrise and Sunset Times for St. Louis Missouri
The sunrise and sunset times below were calculated by the Earth Systems Research Laboratories for NOAA. These times are calculated using equations for Jean Meeus’s Astronomical Algorithms. The atmosphere complicates these calculations due to the refraction of sunlight as it passes through the atmosphere. For the times listed below, the amount of atmospheric refraction is assumed to be 0.833°. Variations in the atmosphere can change the amount of refraction so the times posted are accurate to within a minute for latitudes between +/- 72°.
| Day | Sunrise (CDT) | Sunset (CDT) |
| 1-Oct | 6:57 | 18:43 |
| 2-Oct | 6:58 | 18:42 |
| 3-Oct | 6:59 | 18:40 |
| 4-Oct | 6:59 | 18:39 |
| 5-Oct | 7:00 | 18:37 |
| 6-Oct | 7:01 | 18:36 |
| 7-Oct | 7:02 | 18:34 |
| 8-Oct | 7:03 | 18:33 |
| 9-Oct | 7:04 | 18:31 |
| 10-Oct | 7:05 | 18:30 |
| 11-Oct | 7:06 | 18:28 |
| 12-Oct | 7:07 | 18:27 |
| 13-Oct | 7:08 | 18:25 |
| 14-Oct | 7:09 | 18:24 |
| 15-Oct | 7:10 | 18:22 |
| 16-Oct | 7:11 | 18:21 |
| 17-Oct | 7:12 | 18:19 |
| 18-Oct | 7:13 | 18:18 |
| 19-Oct | 7:14 | 18:17 |
| 20-Oct | 7:15 | 18:15 |
| 21-Oct | 7:16 | 18:14 |
| 22-Oct | 7:17 | 18:13 |
| 23-Oct | 7:18 | 18:11 |
| 24-Oct | 7:19 | 18:10 |
| 25-Oct | 7:20 | 18:09 |
| 26-Oct | 7:21 | 18:08 |
| 27-Oct | 7:22 | 18:06 |
| 28-Oct | 7:23 | 18:05 |
| 29-Oct | 7:24 | 18:04 |
| 30-Oct | 7:25 | 18:03 |
| 31-Oct | 7:26 | 18:02 |
Moon (daytime views)
Last quarter moon occurs on October 3, 2026, and first quarter moon occurs on October 18, 2026. The best daytime views of the Moon are always near the quarter phases. Look for the Moon in the morning at the beginning of October. When we are near first quarter phase, look for the Moon in the afternoon.
The Moon crosses the ecliptic at its descending node this month on October 7, 2026, and then at its ascending node on October 21, 2026. This behavior occurs because the Moon’s orbit around Earth is tilted about 5.1° with respect to Earth’s ecliptic. This nodal cycle of the Moon is called a draconic month which is 27.2 days long. During each nodal cycle, the Moon crosses Earth’s ecliptic twice at what are called the ascending and descending nodes. Being aware of these crossing nodes helps observers know if the Moon will appear south or north of the ecliptic.
| Phase | Date | Time (CDT) |
| Full Moon | September 26, 2026 | 23:49 |
| Last Quarter | October 03, 2026 | 08:25 |
| New Moon | October 10, 2026 | 10:50 |
| First Quarter | October 18, 2026 | 11:13 |
| Full Moon | October 25, 2026 | 23:12 |
Solar Sunday occurs on the third Sunday of the month from 11:00 a.m. until 3:00 p.m. (Weather Dependent).
Each month on the third Sunday, the St. Louis Astronomical Society and the Saint Louis Science Center will set up a number of safe solar telescopes outdoors and be on hand to answer your questions. Telescope viewing begins at 11:00 a.m. and is weather dependent.
The St. Louis Astronomical Society helps host the monthly Star Parties at the Saint Louis Science Center. In addition to our daytime viewings, they also help facilitate our nighttime Public Telescope Viewing. These nighttime viewing sessions occur on the 1st Friday each month. Visit SLAS’s website linked above to learn about other telescope events SLAS hosts around the St. Louis area.
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