Wapinita Airstrip
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Wapinita Airstrip clear sky chart from 2005-11-06 to 2025-10-04.

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	5% 6% 2 6% 4 4 4 4 5% 7% 52%	135670
	Night	6% 7% 3 7% 5% 4 4 4 5% 7% 47%	131030
Transparency	Day	31% 7% 12% 24% 18% 8%	130430
	Night	35% 8% 15% 24% 14% 5%	127268
Seeing	Day	9% 14% 25% 28% 18% 5%	15727
	Night	9% 8% 23% 38% 20% 2	24690

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	11% 17% 7% 14% 7% 7% 6% 5% 6% 6% 13%	3639
	11th to 20th	Day	10% 12% 4 7% 5% 5% 5% 4 4 8% 37%	3640
	21st to end	Day	9% 10% 3 10% 7% 6% 5% 4 6% 7% 32%	4211
February	1st to 10th	Day	8% 12% 5% 9% 7% 4 6% 4 7% 9% 28%	1800
	11th to 20th	Day	9% 9% 3 8% 6% 6% 6% 5% 7% 9% 34%	1755
	21st to end	Day	7% 10% 4 10% 6% 5% 6% 6% 7% 9% 31%	1640
March	1st to 10th	Day	6% 9% 3 7% 5% 5% 6% 5% 9% 10% 34%	4550
	11th to 20th	Day	5% 9% 4 9% 6% 6% 5% 4 6% 7% 38%	5000
	21st to end	Day	5% 8% 4 10% 8% 7% 7% 6% 8% 9% 26%	5743
April	1st to 10th	Day	8% 11% 3 7% 6% 6% 6% 4 7% 8% 33%	2400
	11th to 20th	Day	6% 9% 3 7% 6% 4 5% 5% 5% 7% 44%	2369
	21st to end	Day	4 6% 2 7% 5% 4 6% 4 7% 9% 45%	2517
May	1st to 10th	Day	8% 5% 2 5% 4 3 4 3 5% 6% 55%	6320
	11th to 20th	Day	5% 4 2 5% 4 4 4 3 5% 8% 55%	6277
	21st to end	Day	6% 4 1 4 4 4 4 3 6% 9% 54%	6902
June	1st to 10th	Day	7% 6% 3 6% 5% 4 5% 4 5% 8% 48%	2800
	11th to 20th	Day	5% 4 2 6% 4 4 4 4 5% 7% 56%	2800
	21st to end	Day	3 2 1 3 3 3 3 3 4 6% 69%	2800
July	1st to 10th	Day	1 1 1 2 1 1 2 1 3 4 84%	6319
	11th to 20th	Day	1 1 1 1 1 1 1 3 3 86%	6320
	21st to end	Day	2 1 2 1 1 2 1 3 5% 82%	6880
August	1st to 10th	Day	2 2 1 3 2 2 2 3 4 6% 73%	6024
	11th to 20th	Day	1 1 1 2 2 2 3 3 5% 6% 73%	5796
	21st to end	Day	3 3 1 3 3 3 3 3 5% 6% 67%	5989
September	1st to 10th	Day	2 1 1 3 2 3 3 2 3 6% 76%	2400
	11th to 20th	Day	3 4 2 4 4 3 5% 4 5% 6% 61%	2400
	21st to end	Day	6% 4 2 4 3 4 4 3 4 7% 59%	2140
October	1st to 10th	Day	4 4 2 4 2 2 4 3 6% 6% 61%	3211
	11th to 20th	Day	4 3 1 6% 5% 5% 6% 5% 8% 10% 48%	3161
	21st to end	Day	7% 6% 3 6% 5% 6% 7% 5% 7% 9% 39%	3261
November	1st to 10th	Day	8% 9% 4 9% 6% 6% 6% 5% 7% 9% 31%	1754
	11th to 20th	Day	8% 11% 4 12% 8% 7% 6% 5% 8% 7% 23%	1600
	21st to end	Day	7% 12% 2 9% 7% 7% 6% 6% 7% 8% 30%	1600
December	1st to 10th	Day	6% 8% 3 9% 4 5% 4 4 5% 9% 43%	2620
	11th to 20th	Day	9% 14% 5% 14% 9% 7% 7% 5% 7% 8% 15%	3028
	21st to end	Day	10% 13% 5% 12% 7% 7% 6% 5% 7% 7% 19%	4004
January	1st to 10th	Night	13% 16% 8% 15% 8% 6% 5% 4 5% 6% 13%	6306
	11th to 20th	Night	12% 12% 3 7% 4 4 3 3 5% 10% 37%	6320
	21st to end	Night	10% 11% 5% 10% 5% 5% 4 4 4 6% 35%	6749
February	1st to 10th	Night	8% 14% 4 10% 6% 5% 4 4 7% 7% 31%	2600
	11th to 20th	Night	8% 11% 3 6% 5% 6% 6% 4 5% 8% 38%	2532
	21st to end	Night	7% 11% 4 8% 6% 5% 5% 5% 7% 9% 32%	1988
March	1st to 10th	Night	4 6% 3 8% 6% 6% 6% 5% 8% 10% 38%	5342
	11th to 20th	Night	5% 8% 3 8% 6% 5% 5% 4 6% 7% 43%	5000
	21st to end	Night	6% 7% 3 9% 8% 7% 7% 5% 9% 12% 27%	5231
April	1st to 10th	Night	8% 7% 3 8% 5% 5% 5% 5% 6% 9% 40%	2000
	11th to 20th	Night	6% 6% 2 7% 5% 5% 5% 5% 6% 7% 46%	1979
	21st to end	Night	7% 7% 2 5% 5% 4 4 4 6% 8% 50%	1879
May	1st to 10th	Night	8% 5% 1 4 3 3 2 2 4 6% 63%	3640
	11th to 20th	Night	3 3 2 5% 4 4 4 4 5% 7% 59%	3616
	21st to end	Night	6% 4 1 4 3 3 3 3 5% 9% 59%	3972
June	1st to 10th	Night	9% 6% 3 5% 3 3 4 4 5% 6% 52%	1600
	11th to 20th	Night	5% 4 1 4 4 2 4 3 6% 7% 61%	1600
	21st to end	Night	3 3 1 4 3 2 3 3 4 4 70%	1600
July	1st to 10th	Night	1 1 1 1 2 2 2 3 4 82%	3640
	11th to 20th	Night	1 1 1 1 1 1 1 2 3 86%	3640
	21st to end	Night	1 1 2 1 1 2 1 3 5% 82%	3970
August	1st to 10th	Night	1 2 1 3 2 3 3 3 5% 8% 70%	3761
	11th to 20th	Night	2 1 1 2 3 2 3 2 4 5% 74%	4052
	21st to end	Night	2 2 1 4 2 3 3 3 4 6% 70%	5010
September	1st to 10th	Night	2 2 1 2 2 2 2 2 4 5% 77%	2000
	11th to 20th	Night	4 2 1 3 3 3 4 3 5% 7% 65%	2000
	21st to end	Night	4 3 1 3 3 3 3 3 6% 7% 63%	2257
October	1st to 10th	Night	3 3 1 3 3 3 3 2 4 6% 69%	3836
	11th to 20th	Night	4 4 1 4 4 5% 5% 4 7% 10% 51%	3777
	21st to end	Night	8% 5% 2 6% 5% 5% 6% 5% 8% 8% 41%	4301
November	1st to 10th	Night	9% 8% 3 7% 7% 5% 6% 5% 7% 8% 36%	2544
	11th to 20th	Night	8% 11% 4 10% 6% 6% 6% 4 7% 8% 29%	2800
	21st to end	Night	7% 10% 3 8% 5% 5% 5% 5% 7% 8% 37%	2800
December	1st to 10th	Night	5% 8% 3 8% 5% 4 4 3 5% 11% 43%	4560
	11th to 20th	Night	10% 16% 6% 13% 7% 8% 7% 4 7% 7% 15%	5176
	21st to end	Night	11% 12% 6% 12% 7% 6% 6% 4 5% 7% 24%	6952

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	66% 12% 11% 9% 2	3639
	11th to 20th	Day	46% 7% 16% 22% 8% 1	3640
	21st to end	Day	46% 9% 10% 21% 11% 3	4211
February	1st to 10th	Day	52% 10% 16% 17% 5% 1	1800
	11th to 20th	Day	46% 11% 16% 20% 8%	1764
	21st to end	Day	48% 10% 17% 16% 9% 1	1640
March	1st to 10th	Day	39% 9% 13% 24% 15% 1	4550
	11th to 20th	Day	42% 7% 13% 27% 11%	5000
	21st to end	Day	48% 11% 16% 18% 6%	5743
April	1st to 10th	Day	47% 9% 17% 18% 9%	2400
	11th to 20th	Day	41% 8% 16% 18% 14% 3	2372
	21st to end	Day	33% 10% 16% 27% 12% 2	2517
May	1st to 10th	Day	28% 6% 9% 28% 26% 3	6320
	11th to 20th	Day	27% 6% 15% 30% 20% 2	6280
	21st to end	Day	26% 7% 21% 33% 12% 1	6904
June	1st to 10th	Day	35% 6% 13% 28% 16% 3	2800
	11th to 20th	Day	28% 6% 13% 34% 15% 4	2800
	21st to end	Day	17% 5% 12% 34% 23% 9%	2800
July	1st to 10th	Day	8% 2 5% 18% 32% 34%	6251
	11th to 20th	Day	6% 2 4 10% 32% 45%	6245
	21st to end	Day	9% 2 7% 30% 33% 20%	6681
August	1st to 10th	Day	13% 3 5% 20% 35% 25%	4383
	11th to 20th	Day	13% 4 9% 35% 29% 9%	4195
	21st to end	Day	17% 3 9% 28% 31% 11%	4316
September	1st to 10th	Day	13% 3 9% 30% 30% 15%	2400
	11th to 20th	Day	23% 6% 11% 29% 23% 8%	2400
	21st to end	Day	26% 6% 13% 26% 21% 7%	2140
October	1st to 10th	Day	22% 7% 9% 31% 25% 7%	3211
	11th to 20th	Day	29% 9% 19% 25% 17% 1	3161
	21st to end	Day	38% 8% 14% 27% 12% 1	3261
November	1st to 10th	Day	48% 10% 14% 19% 8% 1	1754
	11th to 20th	Day	56% 11% 15% 13% 4	1600
	21st to end	Day	49% 8% 17% 18% 8% 1	1600
December	1st to 10th	Day	38% 8% 14% 27% 12%	2620
	11th to 20th	Day	62% 10% 16% 11% 1	3028
	21st to end	Day	58% 9% 17% 13% 3	4004
January	1st to 10th	Night	68% 10% 12% 7% 2	6306
	11th to 20th	Night	43% 7% 19% 24% 6% 1	6320
	21st to end	Night	47% 9% 11% 20% 11% 2	6749
February	1st to 10th	Night	51% 9% 18% 17% 6%	2600
	11th to 20th	Night	43% 11% 18% 19% 8%	2534
	21st to end	Night	45% 11% 15% 19% 9% 1	1988
March	1st to 10th	Night	37% 9% 13% 27% 14% 1	5342
	11th to 20th	Night	37% 9% 16% 28% 10%	5000
	21st to end	Night	44% 14% 23% 16% 3	5231
April	1st to 10th	Night	39% 11% 20% 22% 8% 1	2000
	11th to 20th	Night	36% 9% 18% 22% 12% 3	1979
	21st to end	Night	33% 11% 16% 27% 11% 2	1879
May	1st to 10th	Night	24% 6% 8% 29% 33% 1	3637
	11th to 20th	Night	23% 8% 17% 34% 17% 1	3616
	21st to end	Night	22% 8% 28% 31% 9%	3972
June	1st to 10th	Night	33% 8% 13% 30% 14% 2	1600
	11th to 20th	Night	22% 8% 14% 38% 15% 3	1600
	21st to end	Night	19% 4 13% 34% 24% 7%	1600
July	1st to 10th	Night	8% 3 6% 23% 28% 32%	3600
	11th to 20th	Night	7% 2 6% 12% 29% 44%	3592
	21st to end	Night	7% 2 6% 32% 34% 19%	3857
August	1st to 10th	Night	12% 2 7% 18% 37% 24%	2731
	11th to 20th	Night	11% 3 12% 38% 27% 9%	2929
	21st to end	Night	12% 4 12% 29% 31% 11%	3603
September	1st to 10th	Night	12% 3 12% 29% 30% 15%	2000
	11th to 20th	Night	20% 6% 12% 29% 22% 11%	2000
	21st to end	Night	21% 5% 12% 30% 23% 8%	2257
October	1st to 10th	Night	18% 4 12% 35% 28% 3	3836
	11th to 20th	Night	27% 7% 23% 25% 16% 2	3777
	21st to end	Night	35% 9% 17% 26% 12% 1	4301
November	1st to 10th	Night	44% 11% 14% 21% 9% 1	2544
	11th to 20th	Night	50% 10% 16% 18% 5%	2800
	21st to end	Night	41% 10% 19% 22% 7% 1	2800
December	1st to 10th	Night	35% 8% 16% 33% 7%	4560
	11th to 20th	Night	63% 9% 14% 11% 2	5176
	21st to end	Night	54% 9% 18% 14% 5%	6952

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	22% 15% 30% 21% 11% 3	200
	11th to 20th	Day	17% 14% 28% 29% 11% 4	200
	21st to end	Day	12% 15% 26% 29% 15% 4	310
February	1st to 10th	Day	19% 20% 27% 24% 9% 1	400
	11th to 20th	Day	13% 23% 29% 25% 10% 1	395
	21st to end	Day	16% 24% 25% 25% 9% 1	409
March	1st to 10th	Day	15% 21% 28% 28% 8% 1	500
	11th to 20th	Day	10% 20% 27% 30% 11% 2	500
	21st to end	Day	14% 22% 27% 28% 8% 1	550
April	1st to 10th	Day	16% 21% 26% 21% 12% 4	500
	11th to 20th	Day	13% 21% 31% 20% 11% 5%	492
	21st to end	Day	6% 22% 31% 23% 15% 3	500
May	1st to 10th	Day	11% 17% 29% 25% 15% 5%	503
	11th to 20th	Day	16% 15% 23% 26% 15% 5%	528
	21st to end	Day	12% 12% 23% 27% 20% 6%	573
June	1st to 10th	Day	8% 15% 24% 25% 21% 7%	530
	11th to 20th	Day	8% 22% 25% 27% 14% 4	530
	21st to end	Day	3 11% 26% 31% 22% 7%	530
July	1st to 10th	Day	1 6% 29% 34% 24% 6%	526
	11th to 20th	Day	2 10% 24% 31% 27% 7%	524
	21st to end	Day	2 4 24% 33% 25% 11%	575
August	1st to 10th	Day	2 6% 20% 33% 25% 13%	527
	11th to 20th	Day	1 6% 19% 32% 29% 14%	517
	21st to end	Day	4 8% 23% 30% 25% 10%	583
September	1st to 10th	Day	2 7% 20% 32% 29% 9%	530
	11th to 20th	Day	5% 9% 23% 31% 28% 5%	530
	21st to end	Day	10% 9% 20% 32% 23% 5%	530
October	1st to 10th	Day	9% 12% 24% 30% 20% 5%	503
	11th to 20th	Day	9% 15% 21% 28% 22% 5%	490
	21st to end	Day	12% 19% 26% 25% 15% 4	427
November	1st to 10th	Day	14% 16% 25% 33% 11% 1	295
	11th to 20th	Day	14% 16% 29% 23% 16% 4	200
	21st to end	Day	15% 14% 25% 30% 16% 1	200
December	1st to 10th	Day	13% 14% 22% 26% 17% 8%	200
	11th to 20th	Day	18% 17% 34% 28% 4 1	200
	21st to end	Day	15% 20% 27% 24% 13%	220
January	1st to 10th	Night	16% 14% 22% 31% 14% 3	800
	11th to 20th	Night	15% 11% 24% 31% 18% 2	800
	21st to end	Night	14% 8% 21% 36% 19% 2	880
February	1st to 10th	Night	14% 12% 25% 33% 15% 1	800
	11th to 20th	Night	12% 11% 28% 33% 15% 1	784
	21st to end	Night	14% 13% 26% 35% 11%	660
March	1st to 10th	Night	9% 12% 27% 37% 14% 1	800
	11th to 20th	Night	9% 11% 24% 40% 16% 1	800
	21st to end	Night	8% 14% 28% 36% 13% 1	880
April	1st to 10th	Night	12% 10% 29% 31% 17% 2	800
	11th to 20th	Night	8% 12% 30% 31% 16% 3	791
	21st to end	Night	8% 9% 29% 35% 18% 2	679
May	1st to 10th	Night	5% 9% 29% 36% 19% 3	400
	11th to 20th	Night	7% 6% 22% 37% 26% 2	394
	21st to end	Night	5% 5% 18% 45% 25% 2	433
June	1st to 10th	Night	11% 6% 22% 40% 21% 1	400
	11th to 20th	Night	6% 9% 29% 40% 16% 1	400
	21st to end	Night	4 3 23% 47% 23% 1	400
July	1st to 10th	Night	2 1 17% 53% 25% 2	390
	11th to 20th	Night	1 1 18% 55% 22% 3	388
	21st to end	Night	1 1 15% 51% 29% 3	438
August	1st to 10th	Night	1 2 11% 46% 36% 4	476
	11th to 20th	Night	2 1 9% 41% 39% 9%	594
	21st to end	Night	1 3 18% 44% 29% 4	875
September	1st to 10th	Night	2 3 15% 44% 33% 4	800
	11th to 20th	Night	4 2 14% 44% 31% 6%	800
	21st to end	Night	5% 5% 17% 41% 28% 5%	800
October	1st to 10th	Night	8% 3 20% 41% 24% 4	772
	11th to 20th	Night	5% 7% 21% 38% 24% 4	760
	21st to end	Night	11% 8% 24% 37% 17% 3	836
November	1st to 10th	Night	10% 8% 25% 40% 15% 1	780
	11th to 20th	Night	13% 13% 27% 31% 14% 1	800
	21st to end	Night	9% 9% 23% 37% 19% 3	800
December	1st to 10th	Night	13% 10% 22% 35% 17% 3	800
	11th to 20th	Night	15% 11% 24% 35% 14% 1	800
	21st to end	Night	15% 15% 28% 33% 9% 1	880

Page generated at 2025-09-30 22:39:08. Version ac07

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