Lunar Phase Calendar

Monthly moon phases, illumination percentages, and rise/set times — powered by Skyfield.

Optional: Enter your 5-digit US ZIP code to add moon rise and set times.
Back to Space Toolkit

May 2026

Sun Mon Tue Wed Thu Fri Sat
1
🌕
Full Moon
99.8%
🌕 Full Moon
2
🌕
Full Moon
99.3%
3
🌕
Full Moon
96.9%
4
🌖
Waning Gibbous
92.9%
5
🌖
Waning Gibbous
87.4%
6
🌖
Waning Gibbous
80.6%
7
🌗
Last Quarter
72.6%
8
🌗
Last Quarter
63.7%
9
🌗
Last Quarter
54.1%
🌗 Last Quarter
10
🌗
Last Quarter
44.0%
11
🌘
Waning Crescent
33.9%
12
🌘
Waning Crescent
24.1%
13
🌘
Waning Crescent
15.2%
14
🌘
Waning Crescent
7.9%
15
🌑
New Moon
2.8%
16
🌑
New Moon
0.3%
🌑 New Moon
17
🌑
New Moon
0.9%
18
🌒
Waxing Crescent
4.5%
19
🌒
Waxing Crescent
10.7%
20
🌒
Waxing Crescent
19.2%
21
🌓
First Quarter
29.1%
22
🌓
First Quarter
39.8%
23
🌓
First Quarter
50.6%
🌓 First Quarter
24
🌓
First Quarter
61.1%
25
🌔
Waxing Gibbous
70.8%
26
🌔
Waxing Gibbous
79.4%
27
🌔
Waxing Gibbous
86.7%
28
🌔
Waxing Gibbous
92.5%
29
🌔
Waxing Gibbous
96.7%
30
🌕
Full Moon
99.1%
31
🌕
Full Moon
99.8%
🌕 Full Moon

Next Major Phases

🌓
First Quarter
May 23, 2026
11:10 UTC
In 5 days
🌕
Full Moon
May 31, 2026
08:45 UTC
In 13 days
🌗
Last Quarter
June 08, 2026
10:00 UTC
In 21 days
🌑
New Moon
June 15, 2026
02:54 UTC
In 28 days

Phase Reference

Phase Name Illumination Best for Observing
🌑New Moon ~0% Deep sky objects (darkest skies)
🌒Waxing Crescent1–49% Evening crescent, earthshine visible
🌓First Quarter ~50% Lunar terminator & crater detail
🌔Waxing Gibbous 51–99% Mare & highland contrast
🌕Full Moon ~100% Naked-eye features; bright
🌖Waning Gibbous 99–51% Late-night & pre-dawn viewing
🌗Last Quarter ~50% Pre-dawn terminator detail
🌘Waning Crescent49–1% Pre-dawn crescent; near-dark skies

Understanding Lunar Phases

The lunar cycle: The Moon completes one full cycle of phases — from New Moon back to New Moon — every 29.53 days (the synodic period). This calendar uses the Skyfield astronomy library to compute precise illumination and phase angles directly from JPL ephemeris data, so percentages and phase labels are accurate to the minute.

Rise and set times: When a ZIP code is provided, the calendar adds local moonrise and moonset times for each day. These times vary significantly with latitude and can shift by more than an hour across the continental US. On some days the Moon may not rise or set at all — this is normal near the poles or when the Moon's orbital geometry keeps it above (or below) the horizon for a full day.

Related space tools: Find out if tonight is good for stargazing — including twilight windows, satellite passes, and a quality rating — with the Night Sky Planner. Track the ISS in real time with the ISS Tracker, or predict visible passes for dozens of other satellites with the Satellite Pass Predictor.

This tool was created by Ben Crittenden, a Project Management Professional (PMP) with experience in web development and systems administration.