Meeker
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Meeker clear sky chart from 2005-11-06 to 2026-02-16.

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	4 7% 3 6% 4 4 4 4 6% 7% 51%	139994
	Night	4 9% 3 7% 4 4 4 3 5% 7% 50%	138367
Transparency	Day	32% 6% 9% 22% 21% 11%	134852
	Night	34% 5% 10% 23% 20% 8%	134516
Seeing	Day	11% 16% 29% 27% 14% 3	17163
	Night	10% 9% 24% 36% 18% 2	27408

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	4 16% 7% 13% 7% 5% 4 3 5% 6% 30%	4858
	11th to 20th	Day	3 11% 5% 11% 4 3 4 2 4 5% 49%	5340
	21st to end	Day	2 11% 5% 10% 5% 4 3 2 3 5% 49%	5844
February	1st to 10th	Day	5% 16% 4 9% 5% 5% 5% 3 5% 6% 38%	1890
	11th to 20th	Day	5% 19% 5% 10% 5% 4 4 3 4 7% 35%	1800
	21st to end	Day	4 14% 6% 9% 5% 6% 4 3 5% 5% 38%	1644
March	1st to 10th	Day	2 14% 6% 9% 5% 4 4 2 5% 5% 43%	4908
	11th to 20th	Day	3 11% 4 8% 5% 5% 6% 5% 7% 7% 38%	5000
	21st to end	Day	4 14% 5% 9% 6% 6% 6% 4 6% 7% 34%	5519
April	1st to 10th	Day	5% 13% 3 7% 5% 4 4 4 5% 6% 43%	2400
	11th to 20th	Day	7% 13% 3 7% 6% 4 5% 5% 5% 6% 39%	2371
	21st to end	Day	6% 10% 3 7% 5% 4 5% 5% 7% 6% 43%	2434
May	1st to 10th	Day	6% 10% 2 7% 5% 5% 5% 4 7% 8% 40%	5880
	11th to 20th	Day	4 4 2 7% 5% 5% 6% 5% 8% 9% 47%	6114
	21st to end	Day	3 4 2 5% 4 4 5% 4 6% 8% 54%	6925
June	1st to 10th	Day	4 4 2 3 3 4 4 4 7% 8% 55%	2800
	11th to 20th	Day	3 3 1 4 3 3 4 4 5% 7% 64%	2800
	21st to end	Day	2 2 1 3 3 4 3 4 6% 6% 66%	2800
July	1st to 10th	Day	2 2 1 3 4 4 4 3 5% 7% 67%	6339
	11th to 20th	Day	2 3 1 4 3 4 5% 5% 8% 10% 57%	6140
	21st to end	Day	2 2 1 4 3 4 5% 5% 7% 9% 58%	6401
August	1st to 10th	Day	3 3 1 4 4 5% 5% 5% 8% 9% 54%	5779
	11th to 20th	Day	2 2 1 3 3 4 4 4 7% 8% 61%	5754
	21st to end	Day	5% 3 2 5% 4 5% 5% 4 7% 8% 53%	5984
September	1st to 10th	Day	4 2 1 4 3 4 4 3 6% 7% 61%	2400
	11th to 20th	Day	4 3 2 4 4 4 4 3 5% 6% 60%	2380
	21st to end	Day	5% 4 1 4 2 3 3 2 4 6% 65%	2115
October	1st to 10th	Day	4 4 1 3 3 2 2 2 3 5% 71%	3270
	11th to 20th	Day	5% 5% 1 3 4 4 5% 4 6% 9% 55%	3250
	21st to end	Day	6% 7% 2 4 2 3 4 3 5% 5% 59%	3548
November	1st to 10th	Day	5% 8% 2 5% 4 4 4 2 5% 6% 55%	1964
	11th to 20th	Day	6% 11% 2 5% 3 4 3 4 4 6% 51%	1765
	21st to end	Day	4 11% 4 7% 4 3 4 3 5% 6% 50%	1680
December	1st to 10th	Day	4 9% 3 8% 3 3 2 2 3 5% 58%	2700
	11th to 20th	Day	4 11% 3 7% 3 3 3 3 5% 8% 49%	3106
	21st to end	Day	5% 16% 4 10% 5% 4 4 3 5% 7% 37%	4092
January	1st to 10th	Night	5% 15% 7% 12% 5% 5% 4 3 4 5% 35%	8104
	11th to 20th	Night	3 14% 4 9% 4 3 3 2 4 5% 50%	7650
	21st to end	Night	3 13% 4 9% 4 3 4 3 4 5% 48%	8370
February	1st to 10th	Night	5% 14% 4 9% 5% 4 5% 3 5% 7% 39%	2730
	11th to 20th	Night	5% 13% 4 10% 6% 4 4 3 6% 7% 38%	2597
	21st to end	Night	4 14% 4 10% 4 4 3 3 4 7% 42%	1985
March	1st to 10th	Night	3 15% 4 7% 4 4 4 4 5% 6% 45%	4971
	11th to 20th	Night	3 11% 3 6% 4 4 4 3 5% 7% 51%	5000
	21st to end	Night	6% 15% 4 9% 6% 6% 5% 4 6% 7% 32%	5454
April	1st to 10th	Night	7% 13% 3 7% 5% 4 4 3 5% 7% 44%	2000
	11th to 20th	Night	7% 12% 3 6% 4 4 5% 4 6% 6% 42%	1977
	21st to end	Night	7% 10% 3 7% 5% 5% 4 3 6% 7% 43%	1963
May	1st to 10th	Night	7% 9% 2 6% 5% 5% 5% 4 6% 8% 43%	4100
	11th to 20th	Night	7% 6% 2 6% 4 5% 5% 4 7% 8% 45%	3786
	21st to end	Night	6% 5% 2 6% 4 4 4 3 6% 8% 53%	3972
June	1st to 10th	Night	4 3 2 3 3 3 5% 5% 7% 7% 57%	1600
	11th to 20th	Night	4 4 2 4 3 4 3 3 6% 7% 59%	1600
	21st to end	Night	3 2 1 3 2 3 4 4 5% 9% 66%	1600
July	1st to 10th	Night	3 2 1 4 3 4 4 4 6% 8% 61%	3640
	11th to 20th	Night	1 3 1 5% 4 5% 6% 5% 8% 10% 51%	3822
	21st to end	Night	1 2 1 3 3 3 4 3 6% 9% 63%	4472
August	1st to 10th	Night	2 3 1 5% 4 5% 5% 5% 7% 9% 55%	4033
	11th to 20th	Night	2 2 1 4 4 4 5% 4 5% 8% 62%	4095
	21st to end	Night	3 3 1 5% 4 4 5% 5% 8% 10% 53%	4993
September	1st to 10th	Night	4 2 1 3 3 3 4 3 5% 7% 65%	2000
	11th to 20th	Night	4 3 1 4 3 4 3 3 6% 8% 63%	2016
	21st to end	Night	5% 4 1 3 2 3 3 2 4 5% 68%	2285
October	1st to 10th	Night	3 3 1 3 2 2 3 3 4 4 72%	3920
	11th to 20th	Night	4 5% 1 4 2 3 3 3 5% 10% 59%	3898
	21st to end	Night	6% 7% 2 4 3 3 3 2 4 5% 61%	4252
November	1st to 10th	Night	7% 7% 2 5% 3 3 3 3 5% 6% 56%	2532
	11th to 20th	Night	5% 10% 2 5% 3 3 4 3 5% 7% 51%	2851
	21st to end	Night	7% 11% 3 6% 3 3 3 3 4 6% 50%	2940
December	1st to 10th	Night	4 9% 3 6% 3 3 2 2 3 4 60%	4710
	11th to 20th	Night	5% 10% 3 7% 4 4 4 4 5% 7% 47%	5321
	21st to end	Night	8% 15% 5% 9% 5% 4 4 3 4 6% 37%	7128

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	52% 7% 12% 18% 10% 1	4861
	11th to 20th	Day	37% 4 15% 25% 15% 3	5340
	21st to end	Day	40% 4 12% 23% 18% 3	5844
February	1st to 10th	Day	47% 5% 14% 20% 12% 2	1890
	11th to 20th	Day	52% 4 9% 21% 12% 2	1809
	21st to end	Day	46% 6% 9% 20% 16% 3	1644
March	1st to 10th	Day	43% 4 6% 23% 18% 6%	4908
	11th to 20th	Day	42% 7% 10% 28% 11% 1	5000
	21st to end	Day	48% 7% 10% 26% 9% 1	5519
April	1st to 10th	Day	39% 6% 10% 20% 19% 5%	2400
	11th to 20th	Day	43% 6% 8% 21% 19% 4	2374
	21st to end	Day	39% 7% 7% 25% 20% 2	2434
May	1st to 10th	Day	37% 8% 9% 18% 24% 4	5880
	11th to 20th	Day	29% 9% 7% 26% 25% 4	6118
	21st to end	Day	25% 6% 6% 25% 32% 5%	6926
June	1st to 10th	Day	24% 5% 8% 23% 28% 13%	2800
	11th to 20th	Day	20% 5% 6% 14% 29% 25%	2800
	21st to end	Day	17% 4 4 14% 32% 28%	2800
July	1st to 10th	Day	16% 4 5% 10% 19% 46%	6271
	11th to 20th	Day	18% 7% 7% 16% 29% 22%	6065
	21st to end	Day	20% 6% 8% 15% 23% 29%	6217
August	1st to 10th	Day	29% 7% 12% 19% 16% 17%	4208
	11th to 20th	Day	23% 7% 11% 19% 25% 15%	4165
	21st to end	Day	23% 5% 9% 19% 24% 20%	4311
September	1st to 10th	Day	21% 6% 7% 15% 27% 24%	2400
	11th to 20th	Day	25% 4 7% 20% 28% 15%	2380
	21st to end	Day	21% 3 5% 24% 36% 11%	2115
October	1st to 10th	Day	19% 3 5% 16% 34% 23%	3270
	11th to 20th	Day	24% 6% 8% 31% 27% 4	3250
	21st to end	Day	26% 5% 9% 36% 22% 3	3548
November	1st to 10th	Day	32% 3 10% 27% 25% 3	1964
	11th to 20th	Day	34% 4 13% 28% 20% 2	1765
	21st to end	Day	36% 4 13% 29% 16% 3	1680
December	1st to 10th	Day	32% 3 12% 40% 11% 1	2700
	11th to 20th	Day	34% 4 18% 29% 15% 1	3104
	21st to end	Day	48% 4 11% 18% 17% 2	4092
January	1st to 10th	Night	51% 5% 13% 19% 11% 1	8105
	11th to 20th	Night	38% 4 13% 28% 16% 1	7650
	21st to end	Night	39% 3 12% 21% 21% 3	8370
February	1st to 10th	Night	46% 5% 12% 23% 12% 2	2730
	11th to 20th	Night	47% 5% 8% 24% 14% 2	2598
	21st to end	Night	42% 5% 10% 22% 17% 4	1985
March	1st to 10th	Night	39% 5% 6% 26% 18% 6%	4971
	11th to 20th	Night	33% 4 11% 31% 19% 2	5000
	21st to end	Night	50% 6% 12% 22% 9% 1	5454
April	1st to 10th	Night	40% 5% 9% 22% 18% 6%	2000
	11th to 20th	Night	39% 6% 10% 23% 17% 5%	1977
	21st to end	Night	41% 3 8% 25% 20% 2	1963
May	1st to 10th	Night	36% 7% 10% 21% 22% 3	4097
	11th to 20th	Night	34% 7% 9% 28% 20% 2	3787
	21st to end	Night	28% 5% 7% 27% 29% 4	3972
June	1st to 10th	Night	22% 4 11% 25% 24% 14%	1600
	11th to 20th	Night	24% 4 7% 14% 23% 28%	1600
	21st to end	Night	16% 3 5% 15% 30% 31%	1600
July	1st to 10th	Night	19% 5% 7% 9% 19% 40%	3600
	11th to 20th	Night	22% 8% 9% 20% 24% 17%	3774
	21st to end	Night	17% 5% 9% 17% 27% 25%	4344
August	1st to 10th	Night	24% 7% 12% 21% 16% 20%	2928
	11th to 20th	Night	26% 6% 14% 15% 22% 16%	2960
	21st to end	Night	21% 6% 11% 18% 22% 23%	3597
September	1st to 10th	Night	19% 5% 8% 18% 23% 28%	2000
	11th to 20th	Night	21% 4 10% 22% 25% 18%	2016
	21st to end	Night	20% 3 5% 21% 38% 13%	2285
October	1st to 10th	Night	17% 3 5% 16% 37% 23%	3920
	11th to 20th	Night	22% 6% 10% 30% 27% 5%	3898
	21st to end	Night	26% 4 8% 33% 25% 3	4252
November	1st to 10th	Night	30% 4 9% 28% 25% 4	2532
	11th to 20th	Night	32% 5% 12% 30% 19% 3	2851
	21st to end	Night	37% 4 9% 29% 18% 4	2940
December	1st to 10th	Night	29% 3 11% 41% 14% 1	4710
	11th to 20th	Night	37% 4 15% 30% 13%	5322
	21st to end	Night	49% 5% 10% 18% 17% 1	7128

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	24% 14% 25% 24% 10% 2	330
	11th to 20th	Day	13% 16% 35% 26% 8% 2	330
	21st to end	Day	12% 13% 36% 31% 6% 1	363
February	1st to 10th	Day	19% 25% 33% 17% 4 2	330
	11th to 20th	Day	20% 26% 30% 22% 3 1	315
	21st to end	Day	19% 23% 35% 15% 7%	249
March	1st to 10th	Day	19% 30% 28% 17% 6% 1	478
	11th to 20th	Day	12% 28% 34% 19% 6%	500
	21st to end	Day	19% 29% 34% 15% 4	550
April	1st to 10th	Day	17% 26% 30% 20% 6% 2	500
	11th to 20th	Day	18% 29% 32% 16% 4	492
	21st to end	Day	16% 24% 33% 18% 8% 1	500
May	1st to 10th	Day	15% 23% 31% 19% 10% 1	503
	11th to 20th	Day	11% 18% 28% 26% 14% 2	645
	21st to end	Day	9% 17% 28% 28% 15% 4	789
June	1st to 10th	Day	5% 14% 25% 33% 18% 5%	730
	11th to 20th	Day	7% 15% 34% 28% 14% 2	730
	21st to end	Day	4 12% 28% 34% 19% 4	730
July	1st to 10th	Day	3 6% 25% 35% 25% 6%	721
	11th to 20th	Day	3 5% 24% 38% 24% 6%	635
	21st to end	Day	4 6% 24% 38% 22% 6%	575
August	1st to 10th	Day	5% 8% 27% 37% 18% 5%	527
	11th to 20th	Day	5% 5% 27% 36% 21% 6%	517
	21st to end	Day	4 8% 30% 35% 19% 4	583
September	1st to 10th	Day	5% 8% 27% 35% 19% 6%	530
	11th to 20th	Day	5% 13% 37% 26% 15% 4	530
	21st to end	Day	9% 16% 21% 31% 18% 5%	445
October	1st to 10th	Day	13% 14% 19% 27% 22% 4	330
	11th to 20th	Day	11% 16% 28% 27% 18% 1	330
	21st to end	Day	13% 21% 29% 25% 11% 1	363
November	1st to 10th	Day	18% 18% 31% 22% 10% 1	330
	11th to 20th	Day	10% 19% 34% 22% 12% 2	330
	21st to end	Day	14% 16% 29% 30% 10% 1	330
December	1st to 10th	Day	17% 17% 29% 23% 12% 2	330
	11th to 20th	Day	15% 16% 36% 25% 7% 1	330
	21st to end	Day	22% 18% 32% 21% 6% 1	363
January	1st to 10th	Night	14% 11% 25% 35% 12% 2	1018
	11th to 20th	Night	13% 11% 28% 34% 12% 2	840
	21st to end	Night	12% 8% 31% 39% 9% 2	924
February	1st to 10th	Night	13% 12% 33% 32% 9% 1	840
	11th to 20th	Night	12% 14% 30% 35% 9%	804
	21st to end	Night	13% 14% 34% 33% 6%	660
March	1st to 10th	Night	12% 15% 29% 33% 12% 1	800
	11th to 20th	Night	8% 9% 29% 37% 15% 1	800
	21st to end	Night	13% 13% 29% 34% 10% 1	870
April	1st to 10th	Night	13% 15% 28% 36% 8%	600
	11th to 20th	Night	14% 13% 29% 32% 9% 2	593
	21st to end	Night	13% 13% 25% 33% 15% 3	600
May	1st to 10th	Night	12% 11% 28% 33% 15% 1	600
	11th to 20th	Night	9% 8% 22% 36% 21% 4	591
	21st to end	Night	10% 10% 21% 36% 21% 2	650
June	1st to 10th	Night	6% 8% 18% 37% 28% 3	600
	11th to 20th	Night	7% 10% 24% 41% 16% 2	600
	21st to end	Night	4 4 19% 40% 31% 2	600
July	1st to 10th	Night	4 3 15% 36% 38% 5%	585
	11th to 20th	Night	2 2 11% 42% 36% 6%	582
	21st to end	Night	3 1 10% 39% 43% 4	657
August	1st to 10th	Night	5% 3 12% 40% 37% 4	597
	11th to 20th	Night	3 2 10% 45% 36% 3	594
	21st to end	Night	4 2 13% 40% 33% 7%	660
September	1st to 10th	Night	5% 3 13% 41% 35% 4	600
	11th to 20th	Night	5% 4 18% 43% 25% 5%	616
	21st to end	Night	6% 7% 19% 33% 28% 7%	800
October	1st to 10th	Night	8% 6% 22% 39% 21% 4	800
	11th to 20th	Night	9% 7% 24% 38% 19% 3	800
	21st to end	Night	11% 9% 24% 35% 17% 3	880
November	1st to 10th	Night	11% 12% 26% 32% 17% 2	892
	11th to 20th	Night	11% 12% 32% 31% 12% 2	1050
	21st to end	Night	14% 11% 24% 38% 12% 1	1050
December	1st to 10th	Night	15% 10% 29% 34% 12% 1	1050
	11th to 20th	Night	17% 11% 30% 31% 10% 1	1050
	21st to end	Night	19% 12% 33% 30% 5% 1	1155

Page generated at 2026-02-12 23:42:15. Version ac07

Copyright © 2026 Attilla Danko.