Washita Battlefield
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Washita Battlefield clear sky chart from 2005-11-06 to 2025-04-11.

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	7% 5% 2 4 3 3 3 3 5% 6% 59%	117869
	Night	6% 5% 1 4 3 3 3 3 5% 7% 60%	119233
Transparency	Day	26% 4 8% 24% 26% 11%	117636
	Night	24% 4 8% 24% 27% 12%	119056
Seeing	Day	9% 9% 29% 32% 18% 3	15851
	Night	9% 9% 36% 35% 11% 1	25935

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	7% 8% 2 6% 4 4 4 3 4 5% 55%	4077
	11th to 20th	Day	4 5% 3 4 3 3 3 2 3 4 68%	4080
	21st to end	Day	10% 8% 2 6% 3 2 3 2 4 4 56%	4603
February	1st to 10th	Day	6% 9% 3 6% 3 3 3 2 5% 6% 56%	2000
	11th to 20th	Day	7% 6% 2 5% 4 3 3 3 4 6% 58%	1949
	21st to end	Day	5% 5% 2 4 3 3 2 3 4 6% 62%	1650
March	1st to 10th	Day	8% 4 2 5% 2 3 3 3 4 5% 61%	4557
	11th to 20th	Day	6% 4 2 5% 4 3 3 3 5% 7% 59%	4980
	21st to end	Day	6% 6% 3 6% 4 4 4 3 4 6% 55%	5464
April	1st to 10th	Day	9% 5% 1 3 3 2 3 3 5% 7% 60%	2310
	11th to 20th	Day	11% 6% 2 6% 3 4 3 3 4 6% 52%	2252
	21st to end	Day	10% 5% 1 4 4 3 4 3 5% 6% 54%	2440
May	1st to 10th	Day	13% 6% 2 5% 4 4 3 3 4 5% 51%	4120
	11th to 20th	Day	10% 5% 2 5% 3 3 4 3 5% 7% 54%	4082
	21st to end	Day	10% 5% 2 4 4 4 4 3 5% 6% 54%	4489
June	1st to 10th	Day	6% 3 2 4 4 3 6% 4 7% 9% 52%	2470
	11th to 20th	Day	4 4 1 4 4 3 4 3 6% 8% 59%	2470
	21st to end	Day	5% 3 1 4 3 4 4 4 6% 7% 59%	2470
July	1st to 10th	Day	7% 4 2 5% 4 4 5% 5% 7% 8% 48%	4120
	11th to 20th	Day	4 3 1 3 4 4 4 4 6% 9% 58%	4120
	21st to end	Day	3 2 1 3 3 3 4 4 6% 9% 61%	4466
August	1st to 10th	Day	5% 3 1 6% 4 3 4 4 5% 8% 57%	4103
	11th to 20th	Day	4 3 1 4 3 4 4 3 5% 9% 59%	3822
	21st to end	Day	4 3 1 3 3 3 3 4 5% 7% 64%	4180
September	1st to 10th	Day	8% 4 1 4 4 4 3 2 4 6% 58%	2157
	11th to 20th	Day	8% 4 2 5% 4 4 4 4 5% 7% 52%	2090
	21st to end	Day	6% 2 1 4 4 2 3 3 5% 6% 64%	2090
October	1st to 10th	Day	6% 3 1 3 2 2 2 2 2 5% 73%	3480
	11th to 20th	Day	5% 2 1 3 2 2 3 2 4 6% 69%	3280
	21st to end	Day	5% 3 1 3 2 2 2 2 4 6% 69%	3316
November	1st to 10th	Day	6% 4 1 3 3 2 2 2 4 5% 68%	1763
	11th to 20th	Day	4 4 2 3 3 2 2 2 5% 4 69%	1800
	21st to end	Day	8% 5% 2 4 3 3 2 2 4 5% 62%	1800
December	1st to 10th	Day	4 4 2 4 2 3 3 3 4 6% 67%	2940
	11th to 20th	Day	5% 4 1 3 3 2 3 3 4 5% 66%	3391
	21st to end	Day	9% 10% 3 7% 4 4 4 3 5% 4 47%	4488
January	1st to 10th	Night	8% 6% 2 6% 4 4 4 3 5% 5% 52%	5888
	11th to 20th	Night	2 3 1 4 3 3 3 3 4 6% 67%	5900
	21st to end	Night	9% 10% 2 4 3 3 3 3 4 5% 54%	6416
February	1st to 10th	Night	8% 8% 2 6% 3 3 4 3 3 5% 56%	2400
	11th to 20th	Night	9% 6% 2 5% 3 3 3 3 4 6% 54%	2338
	21st to end	Night	6% 6% 2 5% 3 2 3 3 5% 6% 59%	1980
March	1st to 10th	Night	4 6% 2 4 3 3 3 2 4 6% 63%	5312
	11th to 20th	Night	5% 3 1 4 2 3 3 3 4 6% 65%	4980
	21st to end	Night	6% 5% 2 5% 3 3 3 3 5% 7% 57%	5467
April	1st to 10th	Night	6% 5% 1 4 3 3 3 4 5% 7% 59%	2085
	11th to 20th	Night	8% 7% 2 4 2 3 4 3 6% 7% 54%	1882
	21st to end	Night	12% 4 2 3 2 3 3 3 6% 7% 56%	1739
May	1st to 10th	Night	15% 7% 2 5% 3 2 3 3 3 4 52%	2850
	11th to 20th	Night	9% 5% 2 6% 4 4 4 4 5% 8% 50%	2823
	21st to end	Night	9% 4 1 4 2 3 3 3 5% 7% 58%	3098
June	1st to 10th	Night	4 3 1 4 3 3 5% 4 8% 10% 55%	1710
	11th to 20th	Night	4 3 1 4 3 3 3 5% 8% 11% 55%	1710
	21st to end	Night	4 3 1 3 3 3 4 4 6% 8% 61%	1710
July	1st to 10th	Night	6% 4 2 5% 3 4 4 4 6% 8% 54%	2850
	11th to 20th	Night	3 2 1 3 3 3 4 4 7% 12% 57%	2850
	21st to end	Night	2 2 1 3 3 3 4 3 6% 9% 63%	3097
August	1st to 10th	Night	2 2 1 4 3 4 4 4 7% 11% 57%	2836
	11th to 20th	Night	4 3 1 4 3 4 4 4 8% 13% 51%	3013
	21st to end	Night	3 2 1 3 3 3 4 4 6% 9% 63%	3487
September	1st to 10th	Night	7% 3 1 4 3 3 3 3 5% 7% 61%	2022
	11th to 20th	Night	10% 5% 2 4 3 4 3 4 5% 7% 53%	2090
	21st to end	Night	6% 3 2 4 3 3 4 3 4 7% 62%	2090
October	1st to 10th	Night	5% 2 1 2 2 2 3 2 4 5% 73%	3480
	11th to 20th	Night	5% 2 1 3 2 3 3 2 3 6% 71%	3605
	21st to end	Night	5% 2 2 1 2 2 2 4 7% 73%	4234
November	1st to 10th	Night	6% 3 1 3 2 2 3 2 4 5% 68%	2535
	11th to 20th	Night	4 3 1 3 3 3 3 2 3 5% 70%	2600
	21st to end	Night	8% 5% 2 3 3 3 3 2 4 6% 62%	2600
December	1st to 10th	Night	4 3 1 3 2 2 3 2 4 6% 69%	4250
	11th to 20th	Night	4 4 1 4 3 3 2 2 4 6% 66%	4816
	21st to end	Night	10% 9% 2 5% 3 3 3 3 4 5% 52%	6490

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	32% 4 7% 27% 23% 6%	4078
	11th to 20th	Day	23% 2 8% 18% 36% 13%	4080
	21st to end	Day	33% 3 4 20% 31% 9%	4603
February	1st to 10th	Day	32% 3 7% 25% 24% 10%	2000
	11th to 20th	Day	30% 3 8% 25% 25% 9%	1959
	21st to end	Day	25% 3 5% 22% 30% 15%	1650
March	1st to 10th	Day	26% 3 6% 14% 23% 28%	4557
	11th to 20th	Day	25% 3 6% 17% 30% 18%	4980
	21st to end	Day	30% 4 9% 30% 22% 4	5464
April	1st to 10th	Day	26% 3 8% 23% 25% 15%	2310
	11th to 20th	Day	34% 4 7% 21% 22% 12%	2255
	21st to end	Day	30% 5% 10% 25% 24% 6%	2440
May	1st to 10th	Day	34% 7% 10% 16% 21% 12%	4120
	11th to 20th	Day	29% 6% 11% 28% 20% 6%	4086
	21st to end	Day	30% 7% 9% 19% 19% 16%	4489
June	1st to 10th	Day	27% 8% 16% 28% 14% 8%	2470
	11th to 20th	Day	24% 6% 11% 26% 24% 9%	2470
	21st to end	Day	22% 5% 13% 25% 23% 11%	2470
July	1st to 10th	Day	31% 6% 10% 28% 19% 5%	4056
	11th to 20th	Day	21% 6% 10% 31% 26% 6%	4051
	21st to end	Day	18% 6% 11% 31% 30% 4	4325
August	1st to 10th	Day	25% 4 10% 26% 28% 7%	4090
	11th to 20th	Day	22% 6% 9% 26% 29% 9%	3861
	21st to end	Day	20% 4 12% 31% 28% 5%	4179
September	1st to 10th	Day	28% 5% 9% 21% 23% 14%	2157
	11th to 20th	Day	31% 5% 9% 21% 27% 6%	2090
	21st to end	Day	22% 4 9% 22% 32% 11%	2090
October	1st to 10th	Day	17% 2 6% 14% 40% 20%	3480
	11th to 20th	Day	18% 3 9% 24% 26% 20%	3280
	21st to end	Day	18% 3 6% 26% 36% 12%	3316
November	1st to 10th	Day	20% 3 6% 25% 29% 17%	1763
	11th to 20th	Day	19% 3 5% 28% 33% 12%	1800
	21st to end	Day	26% 2 5% 22% 31% 14%	1800
December	1st to 10th	Day	21% 2 7% 37% 27% 7%	2940
	11th to 20th	Day	21% 3 6% 21% 38% 11%	3389
	21st to end	Day	39% 5% 7% 22% 20% 8%	4488
January	1st to 10th	Night	32% 4 9% 31% 21% 4	5888
	11th to 20th	Night	19% 3 11% 19% 32% 15%	5900
	21st to end	Night	34% 3 5% 16% 32% 10%	6416
February	1st to 10th	Night	32% 3 7% 21% 26% 11%	2400
	11th to 20th	Night	32% 3 8% 21% 25% 11%	2338
	21st to end	Night	27% 2 6% 21% 26% 18%	1980
March	1st to 10th	Night	23% 4 5% 16% 23% 30%	5312
	11th to 20th	Night	21% 3 6% 19% 24% 27%	4980
	21st to end	Night	27% 4 10% 26% 26% 7%	5467
April	1st to 10th	Night	25% 5% 9% 19% 26% 16%	2085
	11th to 20th	Night	29% 5% 10% 21% 23% 11%	1882
	21st to end	Night	28% 5% 10% 27% 23% 8%	1739
May	1st to 10th	Night	36% 5% 8% 16% 20% 16%	2850
	11th to 20th	Night	31% 7% 13% 25% 17% 6%	2824
	21st to end	Night	26% 6% 11% 18% 18% 22%	3099
June	1st to 10th	Night	21% 9% 17% 32% 16% 5%	1710
	11th to 20th	Night	21% 7% 14% 26% 24% 7%	1710
	21st to end	Night	20% 5% 13% 26% 24% 11%	1710
July	1st to 10th	Night	27% 5% 11% 34% 20% 3	2805
	11th to 20th	Night	18% 5% 12% 29% 30% 7%	2796
	21st to end	Night	17% 4 12% 28% 33% 5%	2999
August	1st to 10th	Night	19% 5% 12% 25% 30% 9%	2826
	11th to 20th	Night	24% 5% 10% 27% 28% 7%	3040
	21st to end	Night	19% 5% 14% 33% 25% 5%	3487
September	1st to 10th	Night	23% 4 12% 23% 25% 12%	2022
	11th to 20th	Night	31% 5% 9% 19% 28% 8%	2090
	21st to end	Night	22% 5% 7% 23% 30% 12%	2090
October	1st to 10th	Night	16% 3 6% 15% 38% 22%	3480
	11th to 20th	Night	18% 3 6% 21% 35% 17%	3605
	21st to end	Night	14% 2 5% 26% 37% 15%	4234
November	1st to 10th	Night	20% 3 7% 24% 28% 18%	2535
	11th to 20th	Night	19% 3 6% 25% 32% 15%	2600
	21st to end	Night	25% 3 6% 21% 30% 15%	2600
December	1st to 10th	Night	18% 2 6% 37% 31% 6%	4250
	11th to 20th	Night	22% 2 4 23% 37% 12%	4817
	21st to end	Night	34% 4 7% 25% 23% 8%	6490

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	10% 12% 42% 25% 10% 1	300
	11th to 20th	Day	13% 18% 35% 23% 11%	300
	21st to end	Day	8% 13% 45% 26% 7% 1	330
February	1st to 10th	Day	9% 16% 45% 23% 7%	300
	11th to 20th	Day	12% 14% 49% 17% 7% 1	300
	21st to end	Day	9% 21% 43% 18% 8% 1	249
March	1st to 10th	Day	9% 17% 46% 23% 6%	300
	11th to 20th	Day	18% 17% 41% 18% 5% 2	300
	21st to end	Day	15% 15% 44% 22% 3	330
April	1st to 10th	Day	16% 19% 35% 24% 6%	410
	11th to 20th	Day	13% 23% 44% 18% 2	453
	21st to end	Day	13% 20% 36% 24% 7% 1	620
May	1st to 10th	Day	12% 13% 40% 29% 5% 1	653
	11th to 20th	Day	12% 8% 32% 29% 17% 2	675
	21st to end	Day	11% 8% 37% 29% 14% 2	734
June	1st to 10th	Day	6% 5% 25% 39% 21% 5%	680
	11th to 20th	Day	6% 3 32% 39% 18% 1	680
	21st to end	Day	3 4 27% 42% 21% 4	680
July	1st to 10th	Day	9% 1 13% 37% 31% 10%	671
	11th to 20th	Day	3 2 12% 43% 33% 6%	668
	21st to end	Day	4 1 9% 40% 39% 8%	739
August	1st to 10th	Day	5% 1 12% 45% 33% 4	676
	11th to 20th	Day	7% 1 13% 42% 34% 5%	537
	21st to end	Day	5% 1 12% 40% 34% 9%	539
September	1st to 10th	Day	7% 2 11% 40% 32% 7%	367
	11th to 20th	Day	5% 3 16% 44% 25% 7%	300
	21st to end	Day	9% 5% 19% 33% 26% 7%	300
October	1st to 10th	Day	10% 5% 30% 32% 20% 3	300
	11th to 20th	Day	7% 9% 32% 35% 14% 3	300
	21st to end	Day	15% 10% 37% 22% 12% 4	330
November	1st to 10th	Day	10% 9% 35% 34% 10% 2	300
	11th to 20th	Day	8% 16% 35% 26% 12% 3	300
	21st to end	Day	14% 12% 37% 23% 11% 2	300
December	1st to 10th	Day	7% 12% 45% 27% 9% 1	300
	11th to 20th	Day	11% 9% 42% 27% 11% 1	300
	21st to end	Day	15% 19% 38% 21% 7%	330
January	1st to 10th	Night	7% 13% 39% 34% 7%	1000
	11th to 20th	Night	9% 13% 36% 35% 8%	1000
	21st to end	Night	7% 10% 43% 33% 6%	1065
February	1st to 10th	Night	12% 11% 41% 31% 5% 1	800
	11th to 20th	Night	12% 14% 45% 24% 6%	784
	21st to end	Night	11% 16% 43% 27% 3	660
March	1st to 10th	Night	8% 14% 43% 31% 4	777
	11th to 20th	Night	14% 14% 40% 28% 5%	600
	21st to end	Night	12% 15% 46% 24% 4	660
April	1st to 10th	Night	9% 16% 43% 27% 5%	600
	11th to 20th	Night	12% 15% 49% 21% 2	565
	21st to end	Night	14% 12% 41% 27% 5%	570
May	1st to 10th	Night	15% 11% 44% 28% 4	570
	11th to 20th	Night	10% 7% 39% 31% 11% 1	561
	21st to end	Night	8% 8% 39% 33% 11% 1	617
June	1st to 10th	Night	5% 5% 35% 41% 14% 1	570
	11th to 20th	Night	4 5% 47% 37% 7%	570
	21st to end	Night	5% 3 32% 46% 13% 1	570
July	1st to 10th	Night	7% 2 20% 46% 24% 1	555
	11th to 20th	Night	4 18% 53% 22% 2	552
	21st to end	Night	4 12% 55% 28% 2	624
August	1st to 10th	Night	3 1 17% 52% 25% 1	567
	11th to 20th	Night	7% 1 17% 51% 24%	564
	21st to end	Night	5% 1 15% 45% 31% 3	627
September	1st to 10th	Night	8% 2 18% 48% 24% 1	570
	11th to 20th	Night	13% 3 25% 40% 18% 1	570
	21st to end	Night	8% 3 31% 38% 19% 2	570
October	1st to 10th	Night	8% 6% 28% 42% 16% 1	570
	11th to 20th	Night	10% 8% 38% 37% 7%	651
	21st to end	Night	11% 8% 36% 30% 14%	901
November	1st to 10th	Night	8% 8% 36% 38% 10% 1	975
	11th to 20th	Night	6% 11% 42% 33% 8%	1000
	21st to end	Night	11% 12% 33% 33% 11% 1	1000
December	1st to 10th	Night	10% 10% 39% 34% 7% 1	1000
	11th to 20th	Night	11% 11% 43% 29% 6%	1000
	21st to end	Night	12% 14% 38% 31% 6%	1100

Page generated at 2025-04-08 08:17:26. Version ac07

Copyright © 2025 Attilla Danko.