Coffeyville
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Coffeyville clear sky chart from 2005-11-06 to 2026-09-14.

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	10% 6% 2 6% 4 4 4 3 5% 7% 48%	149044
	Night	10% 6% 2 5% 3 3 3 3 5% 7% 53%	142442
Transparency	Day	23% 33% 8% 19% 14% 3	152682
	Night	21% 33% 8% 19% 15% 4	146871
Seeing	Day	14% 9% 27% 28% 18% 4	18110
	Night	13% 8% 31% 33% 13% 1	27831

By Month

Percentage Cloud Cover SE (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	15% 7% 3 7% 3 4 3 2 4 6% 46%	5289
	11th to 20th	Day	6% 8% 3 6% 5% 3 3 3 4 5% 54%	5310
	21st to end	Day	14% 10% 3 6% 3 3 3 2 3 5% 48%	5812
February	1st to 10th	Day	15% 10% 3 6% 5% 3 3 3 3 6% 42%	1890
	11th to 20th	Day	12% 8% 3 7% 4 3 3 3 4 6% 46%	1943
	21st to end	Day	12% 9% 2 5% 4 4 4 3 5% 7% 45%	1780
March	1st to 10th	Day	11% 8% 3 5% 3 3 3 3 4 6% 52%	5046
	11th to 20th	Day	9% 6% 1 4 3 3 4 3 5% 8% 55%	5090
	21st to end	Day	11% 8% 3 8% 5% 5% 5% 4 6% 8% 36%	5583
April	1st to 10th	Day	12% 6% 2 6% 4 4 4 4 5% 7% 47%	2352
	11th to 20th	Day	15% 7% 2 6% 4 4 4 4 5% 7% 42%	2494
	21st to end	Day	18% 8% 3 7% 5% 3 4 3 4 6% 38%	2688
May	1st to 10th	Day	16% 7% 3 6% 4 4 4 3 4 6% 43%	7617
	11th to 20th	Day	11% 5% 2 6% 4 4 4 3 6% 8% 46%	7627
	21st to end	Day	18% 8% 3 7% 4 4 5% 4 5% 7% 34%	8392
June	1st to 10th	Day	6% 5% 2 5% 5% 4 6% 4 7% 9% 47%	2730
	11th to 20th	Day	7% 5% 2 6% 5% 4 5% 4 6% 10% 47%	2730
	21st to end	Day	6% 3 1 4 4 3 4 4 7% 8% 55%	2730
July	1st to 10th	Day	5% 4 2 5% 4 5% 5% 5% 7% 10% 48%	7680
	11th to 20th	Day	5% 5% 2 6% 5% 5% 5% 4 6% 10% 48%	7680
	21st to end	Day	4 4 2 6% 4 5% 5% 4 8% 11% 47%	8337
August	1st to 10th	Day	3 3 1 4 3 4 4 4 6% 8% 60%	6014
	11th to 20th	Day	5% 3 1 5% 4 4 4 4 6% 10% 53%	5948
	21st to end	Day	4 3 2 5% 3 3 3 3 6% 8% 59%	6246
September	1st to 10th	Day	10% 6% 2 4 4 4 3 3 4 6% 53%	2417
	11th to 20th	Day	9% 5% 1 6% 4 4 4 3 5% 8% 50%	2233
	21st to end	Day	9% 4 2 5% 3 4 3 3 5% 6% 56%	2200
October	1st to 10th	Day	9% 5% 2 4 3 3 3 3 5% 7% 56%	2045
	11th to 20th	Day	10% 5% 2 4 2 3 2 3 4 5% 60%	2000
	21st to end	Day	18% 6% 2 5% 3 3 2 3 3 5% 51%	2200
November	1st to 10th	Day	10% 6% 2 3 3 2 3 3 3 6% 59%	2058
	11th to 20th	Day	11% 5% 2 4 3 3 3 3 3 7% 57%	1895
	21st to end	Day	15% 6% 2 6% 2 2 2 2 4 5% 54%	1890
December	1st to 10th	Day	9% 7% 2 5% 3 3 2 3 4 5% 56%	3030
	11th to 20th	Day	10% 6% 2 6% 4 3 4 2 4 5% 54%	3481
	21st to end	Day	19% 16% 5% 7% 4 4 3 3 4 5% 30%	4587
January	1st to 10th	Night	13% 8% 2 6% 3 3 2 2 4 6% 49%	7634
	11th to 20th	Night	6% 5% 2 6% 4 3 4 3 4 6% 57%	7680
	21st to end	Night	15% 8% 3 5% 3 3 3 3 4 5% 48%	8402
February	1st to 10th	Night	14% 9% 2 6% 4 4 3 4 4 6% 44%	2730
	11th to 20th	Night	13% 8% 3 6% 4 3 3 3 4 5% 48%	2580
	21st to end	Night	12% 7% 2 5% 3 2 2 3 5% 6% 53%	2024
March	1st to 10th	Night	13% 7% 2 6% 3 3 3 2 4 4 52%	5029
	11th to 20th	Night	8% 4 1 4 3 2 3 3 5% 6% 61%	5090
	21st to end	Night	11% 5% 2 6% 4 4 4 3 5% 7% 48%	5588
April	1st to 10th	Night	11% 7% 2 4 3 3 3 3 5% 7% 52%	2268
	11th to 20th	Night	14% 6% 2 6% 4 3 3 2 4 6% 50%	2075
	21st to end	Night	17% 6% 3 5% 4 3 3 2 5% 7% 46%	1928
May	1st to 10th	Night	14% 7% 2 6% 4 4 3 3 5% 7% 46%	5266
	11th to 20th	Night	12% 6% 2 6% 4 4 4 3 6% 8% 46%	5265
	21st to end	Night	17% 7% 2 6% 3 3 3 3 5% 8% 44%	5793
June	1st to 10th	Night	5% 4 2 6% 4 4 4 3 5% 10% 52%	1890
	11th to 20th	Night	5% 3 1 4 3 4 4 4 7% 9% 54%	1890
	21st to end	Night	5% 3 1 4 3 4 3 4 5% 10% 59%	1890
July	1st to 10th	Night	5% 3 1 5% 4 4 4 4 7% 10% 52%	5308
	11th to 20th	Night	3 3 2 5% 4 4 4 4 6% 10% 55%	5307
	21st to end	Night	3 3 2 5% 4 4 4 4 7% 12% 53%	5770
August	1st to 10th	Night	2 2 1 3 3 4 3 4 5% 9% 64%	4156
	11th to 20th	Night	4 3 2 5% 4 3 4 4 6% 8% 58%	4118
	21st to end	Night	3 2 1 4 3 3 3 3 5% 7% 65%	4886
September	1st to 10th	Night	8% 5% 1 4 4 3 4 3 5% 6% 58%	2198
	11th to 20th	Night	8% 5% 2 5% 4 4 4 4 6% 7% 51%	2233
	21st to end	Night	7% 4 2 5% 3 3 3 3 4 6% 61%	2200
October	1st to 10th	Night	8% 3 1 4 3 3 4 3 4 6% 62%	2335
	11th to 20th	Night	12% 4 2 4 2 3 3 3 3 6% 59%	2400
	21st to end	Night	13% 6% 2 5% 3 3 3 3 3 5% 55%	2640
November	1st to 10th	Night	10% 5% 1 3 2 2 3 2 4 6% 62%	2460
	11th to 20th	Night	9% 6% 2 4 3 2 2 3 5% 6% 57%	2720
	21st to end	Night	15% 6% 2 4 2 3 2 3 4 5% 54%	2730
December	1st to 10th	Night	8% 6% 2 5% 3 3 3 2 4 5% 59%	4380
	11th to 20th	Night	13% 6% 3 5% 3 3 3 2 4 5% 53%	4946
	21st to end	Night	17% 11% 4 7% 4 3 3 3 4 6% 38%	6633

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	36% 21% 7% 24% 11% 2	5290
	11th to 20th	Day	25% 21% 7% 24% 16% 6%	5310
	21st to end	Day	32% 22% 6% 17% 21% 3	5812
February	1st to 10th	Day	18% 59% 5% 12% 4 2	1890
	11th to 20th	Day	16% 58% 5% 12% 8% 1	1952
	21st to end	Day	15% 58% 2 8% 11% 5%	1780
March	1st to 10th	Day	24% 28% 4 16% 15% 12%	5046
	11th to 20th	Day	16% 29% 6% 16% 20% 13%	5090
	21st to end	Day	30% 31% 9% 23% 7%	5585
April	1st to 10th	Day	16% 59% 5% 10% 7% 2	2352
	11th to 20th	Day	17% 60% 6% 8% 7% 2	2494
	21st to end	Day	20% 60% 6% 9% 5%	2688
May	1st to 10th	Day	33% 24% 7% 19% 16% 2	7655
	11th to 20th	Day	27% 24% 8% 19% 18% 4	7631
	21st to end	Day	39% 24% 10% 13% 13% 1	8405
June	1st to 10th	Day	14% 60% 7% 10% 8% 1	2730
	11th to 20th	Day	15% 60% 6% 12% 7%	2730
	21st to end	Day	10% 59% 8% 14% 8% 1	2730
July	1st to 10th	Day	24% 22% 13% 24% 15% 2	7616
	11th to 20th	Day	26% 22% 12% 22% 13% 5%	7611
	21st to end	Day	23% 22% 17% 29% 9%	8155
August	1st to 10th	Day	17% 26% 10% 21% 24% 3	6000
	11th to 20th	Day	20% 27% 14% 25% 15% 1	5987
	21st to end	Day	18% 27% 16% 29% 10% 1	6245
September	1st to 10th	Day	12% 55% 6% 12% 12% 4	2417
	11th to 20th	Day	14% 57% 7% 15% 7%	2233
	21st to end	Day	15% 57% 5% 12% 9% 2	2200
October	1st to 10th	Day	10% 36% 4 8% 29% 12%	3331
	11th to 20th	Day	6% 35% 2 18% 29% 10%	3240
	21st to end	Day	18% 36% 3 19% 21% 4	3538
November	1st to 10th	Day	15% 54% 3 14% 12% 3	2058
	11th to 20th	Day	15% 53% 3 13% 12% 4	1895
	21st to end	Day	18% 53% 4 14% 11% 1	1890
December	1st to 10th	Day	20% 34% 4 27% 15%	3030
	11th to 20th	Day	22% 30% 4 23% 18% 2	3479
	21st to end	Day	49% 27% 5% 15% 4	4587
January	1st to 10th	Night	33% 21% 9% 23% 13% 1	7635
	11th to 20th	Night	23% 22% 7% 21% 22% 5%	7680
	21st to end	Night	32% 22% 9% 14% 21% 3	8402
February	1st to 10th	Night	17% 59% 5% 11% 6% 2	2730
	11th to 20th	Night	18% 58% 4 11% 7% 1	2581
	21st to end	Night	13% 59% 2 9% 12% 5%	2024
March	1st to 10th	Night	27% 29% 4 15% 19% 5%	5029
	11th to 20th	Night	14% 28% 4 18% 26% 10%	5090
	21st to end	Night	23% 30% 9% 26% 11% 1	5588
April	1st to 10th	Night	14% 59% 5% 10% 9% 2	2268
	11th to 20th	Night	15% 60% 6% 11% 7% 1	2075
	21st to end	Night	17% 60% 5% 11% 7% 1	1928
May	1st to 10th	Night	30% 25% 10% 18% 16% 1	5293
	11th to 20th	Night	29% 24% 8% 19% 15% 5%	5266
	21st to end	Night	33% 23% 11% 19% 12% 2	5805
June	1st to 10th	Night	12% 60% 9% 10% 8% 2	1890
	11th to 20th	Night	11% 59% 7% 13% 8%	1890
	21st to end	Night	11% 58% 6% 15% 10%	1890
July	1st to 10th	Night	21% 22% 14% 25% 16% 2	5265
	11th to 20th	Night	20% 23% 11% 28% 13% 4	5256
	21st to end	Night	18% 21% 16% 33% 11%	5641
August	1st to 10th	Night	12% 26% 9% 21% 25% 7%	4146
	11th to 20th	Night	18% 27% 12% 24% 18% 1	4145
	21st to end	Night	14% 27% 12% 29% 17% 1	4886
September	1st to 10th	Night	12% 55% 5% 13% 11% 4	2198
	11th to 20th	Night	14% 57% 6% 14% 9% 1	2233
	21st to end	Night	14% 57% 5% 12% 11% 1	2200
October	1st to 10th	Night	8% 36% 3 7% 32% 14%	3816
	11th to 20th	Night	10% 36% 3 13% 25% 14%	3899
	21st to end	Night	18% 36% 4 19% 18% 5%	4252
November	1st to 10th	Night	14% 53% 3 12% 13% 4	2460
	11th to 20th	Night	13% 54% 4 12% 13% 5%	2720
	21st to end	Night	18% 54% 4 12% 12% 1	2730
December	1st to 10th	Night	17% 34% 7% 29% 12% 1	4380
	11th to 20th	Night	24% 30% 4 18% 19% 4	4947
	21st to end	Night	41% 26% 5% 18% 8% 2	6633

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	21% 13% 34% 26% 5% 1	330
	11th to 20th	Day	21% 19% 38% 19% 3	330
	21st to end	Day	17% 15% 40% 21% 6% 1	363
February	1st to 10th	Day	24% 15% 33% 23% 4 1	330
	11th to 20th	Day	21% 16% 39% 20% 3	330
	21st to end	Day	21% 23% 37% 16% 3	273
March	1st to 10th	Day	21% 18% 37% 18% 5% 1	330
	11th to 20th	Day	24% 18% 34% 20% 4	330
	21st to end	Day	21% 20% 36% 18% 4 1	363
April	1st to 10th	Day	17% 18% 38% 20% 6% 1	372
	11th to 20th	Day	21% 20% 34% 21% 4	532
	21st to end	Day	23% 15% 31% 22% 8% 1	708
May	1st to 10th	Day	16% 11% 37% 26% 9% 1	753
	11th to 20th	Day	17% 9% 32% 26% 13% 3	775
	21st to end	Day	17% 10% 28% 23% 17% 6%	844
June	1st to 10th	Day	8% 4 20% 35% 27% 6%	780
	11th to 20th	Day	8% 4 24% 40% 20% 4	780
	21st to end	Day	6% 4 26% 39% 21% 3	780
July	1st to 10th	Day	8% 2 14% 33% 31% 12%	771
	11th to 20th	Day	4 1 15% 37% 33% 9%	768
	21st to end	Day	7% 1 11% 35% 34% 12%	849
August	1st to 10th	Day	5% 3 15% 40% 30% 7%	776
	11th to 20th	Day	6% 2 15% 38% 32% 7%	765
	21st to end	Day	8% 1 11% 32% 40% 9%	706
September	1st to 10th	Day	11% 2 10% 34% 34% 9%	467
	11th to 20th	Day	4 2 17% 39% 27% 11%	339
	21st to end	Day	12% 4 22% 34% 22% 7%	330
October	1st to 10th	Day	9% 7% 24% 33% 19% 8%	330
	11th to 20th	Day	10% 10% 42% 26% 12%	330
	21st to end	Day	25% 10% 34% 21% 8% 2	363
November	1st to 10th	Day	18% 10% 35% 24% 12% 1	330
	11th to 20th	Day	15% 15% 36% 19% 12% 2	330
	21st to end	Day	21% 15% 35% 19% 9% 1	330
December	1st to 10th	Day	15% 15% 42% 18% 8% 2	330
	11th to 20th	Day	18% 12% 41% 22% 7% 1	330
	21st to end	Day	20% 18% 39% 19% 4	363
January	1st to 10th	Night	14% 13% 38% 28% 7%	1050
	11th to 20th	Night	15% 14% 40% 25% 5%	1050
	21st to end	Night	14% 12% 40% 30% 4	1155
February	1st to 10th	Night	18% 14% 39% 25% 4	1050
	11th to 20th	Night	18% 16% 36% 26% 4	946
	21st to end	Night	17% 13% 38% 28% 3	640
March	1st to 10th	Night	16% 13% 35% 32% 4	630
	11th to 20th	Night	19% 13% 37% 26% 5%	630
	21st to end	Night	18% 11% 41% 26% 5%	693
April	1st to 10th	Night	14% 13% 39% 28% 5%	630
	11th to 20th	Night	17% 12% 38% 27% 5%	623
	21st to end	Night	20% 9% 39% 25% 7%	630
May	1st to 10th	Night	15% 7% 35% 35% 7%	630
	11th to 20th	Night	15% 6% 31% 31% 16% 1	621
	21st to end	Night	14% 5% 24% 36% 19% 1	683
June	1st to 10th	Night	8% 2 22% 39% 28% 1	630
	11th to 20th	Night	7% 2 24% 47% 20%	630
	21st to end	Night	5% 3 28% 45% 17% 1	630
July	1st to 10th	Night	7% 1 14% 43% 32% 3	615
	11th to 20th	Night	5% 2 12% 47% 31% 4	612
	21st to end	Night	6% 1 11% 44% 34% 4	690
August	1st to 10th	Night	4 2 17% 44% 32% 1	627
	11th to 20th	Night	7% 2 12% 47% 29% 2	624
	21st to end	Night	4 1 12% 43% 37% 2	693
September	1st to 10th	Night	9% 2 14% 44% 29% 2	630
	11th to 20th	Night	11% 2 14% 43% 27% 3	609
	21st to end	Night	8% 3 20% 42% 24% 3	600
October	1st to 10th	Night	9% 2 28% 36% 22% 2	735
	11th to 20th	Night	14% 7% 37% 32% 10% 1	800
	21st to end	Night	16% 10% 35% 30% 8% 1	880
November	1st to 10th	Night	12% 6% 39% 32% 10% 1	820
	11th to 20th	Night	13% 11% 36% 31% 8%	1040
	21st to end	Night	18% 12% 34% 28% 8%	1050
December	1st to 10th	Night	15% 11% 36% 31% 6%	1050
	11th to 20th	Night	19% 10% 36% 29% 6%	1050
	21st to end	Night	17% 13% 36% 30% 4	1155

Page generated at 2026-09-11 03:11:53. Version ac07

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