Lunar Crater
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lunar Crater clear sky chart from 2005-11-06 to 2024-11-12.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.

Observation Type	Minimum conditions for hour to be usable				Out of hours
	Clear of Clouds	Transparency	Seeing	Sky Brightness
Planetary:	50%	(no limit)	Average	(no limit)	Nighttime Hours
Deep Sky:	70%	Average	(no limit)	5.9	Nighttime Hours
CCD Imaging:	70%	Below Average	Poor	(no limit)	Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

By Month

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

		Occurrence of each Forecast	Data Points
Cloud Cover	Day	3 4 1 4 3 3 3 3 4 6% 65%	105059
	Night	3 4 2 4 3 3 4 3 5% 6% 63%	102846
Transparency	Day	18% 5% 8% 18% 25% 27%	104811
	Night	20% 5% 10% 19% 24% 21%	102683
Seeing	Day	5% 7% 19% 31% 26% 12%	15012
	Night	5% 4 19% 43% 27% 3	24656

By Month

Percentage Cloud Cover SW (2006-)
Color Meanings: Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	3 5% 2 6% 5% 3 4 4 5% 10% 53%	2539
	11th to 20th	Day	5% 6% 2 6% 5% 4 5% 3 7% 9% 47%	2540
	21st to end	Day	6% 8% 3 7% 4 5% 4 4 7% 11% 42%	3126
February	1st to 10th	Day	5% 4 2 6% 3 3 5% 4 6% 9% 54%	1900
	11th to 20th	Day	5% 6% 2 5% 6% 5% 5% 3 4 8% 52%	1850
	21st to end	Day	4 8% 2 4 4 4 3 4 5% 8% 55%	1570
March	1st to 10th	Day	2 7% 2 6% 4 4 5% 4 6% 9% 52%	3138
	11th to 20th	Day	2 6% 2 5% 4 3 4 4 6% 8% 57%	3391
	21st to end	Day	4 9% 3 6% 5% 5% 4 5% 7% 9% 44%	3935
April	1st to 10th	Day	3 5% 2 5% 4 4 4 4 5% 6% 59%	2280
	11th to 20th	Day	4 5% 2 4 3 3 3 4 4 6% 63%	2249
	21st to end	Day	4 4 1 4 3 3 3 3 5% 6% 65%	2418
May	1st to 10th	Day	2 4 1 4 2 3 3 3 3 5% 69%	4110
	11th to 20th	Day	3 3 1 4 3 3 4 3 5% 6% 66%	4071
	21st to end	Day	3 3 2 4 4 3 3 3 4 5% 67%	4477
June	1st to 10th	Day	2 3 1 3 3 3 3 3 5% 8% 65%	2597
	11th to 20th	Day	2 2 1 3 2 3 3 2 3 5% 74%	2660
	21st to end	Day	2 2 1 2 2 2 3 2 3 5% 77%	2660
July	1st to 10th	Day	1 1 1 2 2 2 2 2 3 3 81%	4420
	11th to 20th	Day	2 2 1 3 3 3 4 4 6% 7% 65%	4420
	21st to end	Day	2 2 1 3 3 4 4 4 6% 5% 65%	4498
August	1st to 10th	Day	2 2 1 3 2 2 2 2 3 4 75%	4092
	11th to 20th	Day	1 1 1 1 2 2 2 3 4 83%	3786
	21st to end	Day	2 2 1 2 1 2 2 2 2 3 81%	4180
September	1st to 10th	Day	2 2 1 2 3 3 3 3 4 4 74%	2252
	11th to 20th	Day	2 2 1 2 2 2 3 2 3 6% 76%	2090
	21st to end	Day	2 2 1 2 2 1 2 2 3 4 80%	2090
October	1st to 10th	Day	2 1 1 3 2 2 2 3 4 5% 76%	3490
	11th to 20th	Day	1 2 1 2 2 2 2 2 3 5% 78%	3326
	21st to end	Day	2 2 1 3 2 2 2 2 3 6% 76%	3101
November	1st to 10th	Day	2 4 1 3 2 4 3 3 5% 8% 64%	1764
	11th to 20th	Day	1 3 1 2 1 2 3 3 4 9% 70%	1719
	21st to end	Day	3 5% 1 4 4 4 3 3 4 6% 64%	1710
December	1st to 10th	Day	4 5% 2 4 3 2 4 3 5% 7% 61%	1710
	11th to 20th	Day	7% 10% 3 6% 4 4 4 4 5% 9% 44%	2106
	21st to end	Day	3 5% 2 5% 5% 5% 5% 5% 7% 9% 50%	2794
January	1st to 10th	Night	3 5% 2 6% 5% 4 4 3 5% 7% 57%	4406
	11th to 20th	Night	3 5% 2 6% 5% 6% 6% 4 5% 10% 49%	4420
	21st to end	Night	8% 10% 2 5% 4 5% 4 3 5% 9% 46%	4532
February	1st to 10th	Night	4 5% 2 5% 4 3 4 4 5% 8% 56%	2280
	11th to 20th	Night	4 7% 1 4 3 4 4 4 5% 7% 57%	2218
	21st to end	Night	3 7% 2 5% 4 4 4 3 5% 6% 58%	1884
March	1st to 10th	Night	2 6% 2 5% 4 4 5% 3 4 6% 58%	3736
	11th to 20th	Night	3 6% 2 6% 5% 4 4 3 5% 7% 54%	3588
	21st to end	Night	4 7% 2 6% 3 4 4 3 5% 7% 54%	3715
April	1st to 10th	Night	5% 5% 2 4 3 3 4 3 5% 6% 61%	1900
	11th to 20th	Night	3 5% 2 4 3 3 4 3 4 5% 64%	1879
	21st to end	Night	4 5% 1 5% 3 2 3 2 5% 5% 64%	1761
May	1st to 10th	Night	3 3 1 4 3 3 3 3 5% 7% 65%	2860
	11th to 20th	Night	5% 4 1 4 3 3 3 2 5% 6% 63%	2834
	21st to end	Night	4 4 2 6% 4 4 4 4 5% 6% 59%	3110
June	1st to 10th	Night	3 2 1 2 3 3 4 3 5% 8% 65%	1577
	11th to 20th	Night	3 3 1 3 2 3 2 2 4 5% 72%	1520
	21st to end	Night	2 2 1 2 2 3 2 3 4 5% 73%	1520
July	1st to 10th	Night	3 2 1 2 2 2 3 2 3 3 78%	2540
	11th to 20th	Night	3 3 2 4 4 4 4 3 5% 8% 59%	2540
	21st to end	Night	3 3 2 6% 7% 5% 5% 4 5% 5% 54%	3063
August	1st to 10th	Night	5% 4 1 3 3 3 4 3 5% 6% 63%	2847
	11th to 20th	Night	2 1 1 2 1 2 2 2 2 4 82%	3057
	21st to end	Night	2 1 2 2 2 2 2 3 5% 80%	3498
September	1st to 10th	Night	3 2 1 2 2 2 3 2 5% 5% 74%	1928
	11th to 20th	Night	2 2 1 3 2 2 3 3 4 5% 74%	2090
	21st to end	Night	2 2 1 2 1 2 2 1 2 4 80%	2090
October	1st to 10th	Night	3 2 1 4 2 2 2 2 3 4 74%	3490
	11th to 20th	Night	3 3 1 2 2 2 3 2 3 5% 74%	3605
	21st to end	Night	1 3 1 3 3 2 3 2 3 4 74%	4457
November	1st to 10th	Night	3 3 1 3 2 2 2 2 5% 7% 69%	2535
	11th to 20th	Night	2 3 1 3 3 2 3 3 5% 7% 69%	2483
	21st to end	Night	2 4 1 4 3 3 4 3 5% 6% 65%	2470
December	1st to 10th	Night	4 5% 2 5% 3 4 4 3 5% 7% 58%	2470
	11th to 20th	Night	7% 7% 3 6% 4 4 4 4 5% 9% 47%	3081
	21st to end	Night	3 6% 3 7% 6% 6% 6% 4 6% 9% 45%	4862

Transparency (when cloud cover <= 30%)
Color Meanings: Too cloudy to forecast Poor Below Average Average Above average Transparent
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	24% 9% 19% 33% 14% 1	2539
	11th to 20th	Day	28% 8% 19% 28% 13% 3	2540
	21st to end	Day	33% 10% 18% 23% 13% 2	3126
February	1st to 10th	Day	25% 6% 14% 28% 21% 6%	1900
	11th to 20th	Day	29% 5% 11% 26% 25% 5%	1860
	21st to end	Day	25% 6% 13% 29% 23% 4	1570
March	1st to 10th	Day	25% 6% 10% 27% 25% 7%	3138
	11th to 20th	Day	23% 9% 11% 27% 24% 5%	3391
	21st to end	Day	29% 9% 15% 26% 17% 4	3935
April	1st to 10th	Day	25% 5% 10% 24% 23% 14%	2280
	11th to 20th	Day	20% 5% 9% 21% 29% 15%	2252
	21st to end	Day	19% 4 9% 23% 35% 10%	2418
May	1st to 10th	Day	16% 4 5% 21% 39% 16%	4110
	11th to 20th	Day	16% 4 5% 15% 36% 24%	4074
	21st to end	Day	17% 5% 6% 15% 38% 19%	4477
June	1st to 10th	Day	16% 3 7% 17% 28% 30%	2597
	11th to 20th	Day	13% 3 4 10% 27% 44%	2660
	21st to end	Day	10% 2 3 6% 21% 57%	2660
July	1st to 10th	Day	9% 2 2 4 9% 73%	4351
	11th to 20th	Day	15% 4 6% 8% 18% 50%	4345
	21st to end	Day	16% 6% 7% 13% 18% 39%	4356
August	1st to 10th	Day	13% 2 3 10% 27% 45%	4078
	11th to 20th	Day	7% 2 3 6% 17% 65%	3824
	21st to end	Day	10% 2 3 7% 19% 59%	4179
September	1st to 10th	Day	13% 4 5% 8% 22% 48%	2252
	11th to 20th	Day	10% 3 5% 14% 26% 41%	2090
	21st to end	Day	10% 2 3 11% 36% 39%	2090
October	1st to 10th	Day	10% 2 5% 9% 33% 41%	3490
	11th to 20th	Day	11% 2 3 15% 36% 32%	3326
	21st to end	Day	11% 2 3 24% 47% 13%	3101
November	1st to 10th	Day	18% 3 10% 28% 29% 12%	1764
	11th to 20th	Day	13% 4 10% 31% 34% 7%	1719
	21st to end	Day	20% 3 12% 26% 31% 7%	1710
December	1st to 10th	Day	22% 6% 14% 28% 22% 8%	1710
	11th to 20th	Day	34% 8% 13% 24% 18% 3	2105
	21st to end	Day	28% 8% 18% 23% 19% 4	2794
January	1st to 10th	Night	25% 6% 19% 31% 17% 1	4406
	11th to 20th	Night	27% 8% 20% 28% 13% 4	4420
	21st to end	Night	31% 11% 19% 23% 14% 2	4532
February	1st to 10th	Night	25% 5% 15% 30% 21% 5%	2280
	11th to 20th	Night	25% 5% 14% 22% 27% 7%	2219
	21st to end	Night	25% 4 15% 27% 24% 5%	1884
March	1st to 10th	Night	23% 7% 11% 28% 26% 5%	3736
	11th to 20th	Night	25% 9% 12% 28% 21% 5%	3588
	21st to end	Night	24% 7% 15% 27% 22% 5%	3715
April	1st to 10th	Night	23% 4 11% 28% 23% 11%	1900
	11th to 20th	Night	21% 4 8% 26% 27% 14%	1879
	21st to end	Night	22% 3 8% 24% 35% 9%	1761
May	1st to 10th	Night	14% 6% 7% 17% 40% 15%	2860
	11th to 20th	Night	16% 8% 8% 14% 36% 19%	2835
	21st to end	Night	21% 8% 7% 14% 34% 17%	3110
June	1st to 10th	Night	12% 5% 8% 16% 30% 29%	1577
	11th to 20th	Night	14% 3 5% 9% 25% 43%	1520
	21st to end	Night	12% 3 4 7% 23% 52%	1520
July	1st to 10th	Night	11% 2 3 5% 7% 71%	2500
	11th to 20th	Night	19% 5% 5% 9% 18% 44%	2492
	21st to end	Night	26% 7% 9% 11% 11% 37%	2967
August	1st to 10th	Night	19% 3 5% 9% 26% 39%	2838
	11th to 20th	Night	7% 3 4 6% 14% 66%	3085
	21st to end	Night	8% 2 4 7% 19% 60%	3498
September	1st to 10th	Night	11% 3 6% 8% 22% 50%	1928
	11th to 20th	Night	12% 3 5% 11% 26% 42%	2090
	21st to end	Night	11% 1 3 12% 28% 44%	2090
October	1st to 10th	Night	14% 3 5% 9% 26% 43%	3490
	11th to 20th	Night	14% 3 3 13% 34% 33%	3605
	21st to end	Night	15% 2 3 17% 45% 18%	4457
November	1st to 10th	Night	15% 3 10% 25% 32% 15%	2535
	11th to 20th	Night	14% 4 9% 28% 36% 9%	2483
	21st to end	Night	18% 3 10% 27% 33% 9%	2470
December	1st to 10th	Night	25% 6% 13% 25% 24% 8%	2470
	11th to 20th	Night	29% 8% 13% 26% 20% 3	3081
	21st to end	Night	33% 8% 16% 22% 18% 3	4862

Seeing (when cloud cover <= 80%)
Color Meanings: Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	11% 3 18% 39% 23% 6%	180
	11th to 20th	Day	9% 6% 12% 33% 28% 12%	180
	21st to end	Day	7% 5% 13% 32% 32% 11%	307
February	1st to 10th	Day	6% 7% 26% 32% 20% 8%	460
	11th to 20th	Day	8% 9% 19% 38% 18% 7%	455
	21st to end	Day	4 10% 26% 38% 17% 5%	382
March	1st to 10th	Day	10% 12% 24% 29% 20% 4	460
	11th to 20th	Day	6% 13% 26% 33% 16% 6%	460
	21st to end	Day	10% 15% 32% 29% 12% 3	506
April	1st to 10th	Day	6% 17% 25% 27% 18% 7%	460
	11th to 20th	Day	8% 16% 29% 26% 18% 4	452
	21st to end	Day	7% 13% 25% 29% 16% 10%	460
May	1st to 10th	Day	5% 13% 28% 28% 19% 6%	463
	11th to 20th	Day	7% 10% 21% 28% 23% 11%	488
	21st to end	Day	6% 9% 21% 28% 25% 12%	529
June	1st to 10th	Day	3 9% 18% 28% 27% 16%	490
	11th to 20th	Day	4 10% 23% 27% 26% 10%	490
	21st to end	Day	3 3 19% 31% 32% 12%	490
July	1st to 10th	Day	3 1 15% 35% 34% 12%	486
	11th to 20th	Day	3 1 12% 31% 37% 16%	484
	21st to end	Day	4 2 9% 33% 35% 17%	531
August	1st to 10th	Day	4 2 18% 35% 26% 15%	487
	11th to 20th	Day	3 4 15% 27% 30% 22%	477
	21st to end	Day	2 3 13% 31% 32% 19%	539
September	1st to 10th	Day	2 5% 14% 28% 29% 22%	490
	11th to 20th	Day	2 9% 17% 28% 29% 14%	490
	21st to end	Day	3 6% 14% 28% 35% 14%	490
October	1st to 10th	Day	1 8% 20% 28% 26% 17%	490
	11th to 20th	Day	4 6% 18% 25% 30% 17%	443
	21st to end	Day	4 5% 15% 34% 31% 12%	330
November	1st to 10th	Day	4 5% 21% 30% 26% 14%	300
	11th to 20th	Day	1 5% 11% 44% 22% 16%	273
	21st to end	Day	4 3 16% 31% 31% 14%	270
December	1st to 10th	Day	7% 4 14% 37% 29% 10%	270
	11th to 20th	Day	6% 4 15% 39% 29% 8%	252
	21st to end	Day	7% 9% 16% 34% 26% 8%	198
January	1st to 10th	Night	5% 4 19% 42% 24% 6%	760
	11th to 20th	Night	4 2 19% 45% 25% 5%	760
	21st to end	Night	7% 3 19% 43% 22% 5%	836
February	1st to 10th	Night	7% 3 24% 43% 21% 3	760
	11th to 20th	Night	6% 4 23% 44% 20% 3	744
	21st to end	Night	5% 5% 27% 45% 16% 3	628
March	1st to 10th	Night	6% 6% 24% 45% 18% 2	760
	11th to 20th	Night	5% 6% 23% 41% 21% 3	760
	21st to end	Night	7% 8% 29% 40% 14% 1	836
April	1st to 10th	Night	5% 8% 25% 42% 19% 1	760
	11th to 20th	Night	5% 8% 30% 38% 18% 2	751
	21st to end	Night	6% 6% 29% 37% 19% 3	621
May	1st to 10th	Night	5% 7% 30% 41% 15% 2	570
	11th to 20th	Night	6% 7% 19% 41% 25% 2	561
	21st to end	Night	6% 7% 22% 38% 24% 3	617
June	1st to 10th	Night	2 4 17% 44% 31% 2	437
	11th to 20th	Night	3 4 22% 47% 24% 1	380
	21st to end	Night	2 2 14% 53% 29% 1	380
July	1st to 10th	Night	4 9% 51% 34% 2	370
	11th to 20th	Night	3 1 6% 48% 39% 3	368
	21st to end	Night	4 1 7% 48% 38% 2	591
August	1st to 10th	Night	5% 2 13% 51% 28% 1	567
	11th to 20th	Night	2 1 9% 42% 42% 4	707
	21st to end	Night	1 1 10% 41% 44% 3	836
September	1st to 10th	Night	2 2 11% 35% 46% 4	760
	11th to 20th	Night	2 3 14% 40% 37% 4	760
	21st to end	Night	3 2 14% 39% 35% 7%	760
October	1st to 10th	Night	4 2 18% 42% 30% 4	760
	11th to 20th	Night	5% 1 14% 41% 34% 5%	760
	21st to end	Night	3 2 20% 38% 33% 5%	836
November	1st to 10th	Night	4 4 17% 37% 32% 6%	780
	11th to 20th	Night	3 1 17% 47% 27% 5%	764
	21st to end	Night	3 1 21% 41% 29% 4	760
December	1st to 10th	Night	7% 2 18% 50% 19% 5%	760
	11th to 20th	Night	8% 3 20% 44% 22% 3	760
	21st to end	Night	6% 3 24% 47% 19% 2	836

Page generated at 2024-11-08 19:45:34. Version ac07

Copyright © 2024 Attilla Danko.