Woods Crossroads
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Woods Crossroads clear sky chart from 2005-11-06 to 2026-07-01.

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	13% 6% 2 6% 4 4 5% 4 6% 8% 43%	137559
	Night	14% 6% 2 6% 4 4 4 3 5% 7% 44%	134837
Transparency	Day	26% 36% 8% 15% 12% 3	141151
	Night	26% 36% 7% 16% 13% 3	139316
Seeing	Day	18% 14% 30% 23% 11% 3	17325
	Night	17% 12% 30% 28% 11% 1	26904

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	13% 4 2 5% 3 3 3 3 4 5% 54%	4934
	11th to 20th	Day	12% 6% 2 5% 3 3 3 3 4 5% 55%	5280
	21st to end	Day	13% 8% 3 6% 4 4 4 3 5% 5% 45%	5780
February	1st to 10th	Day	13% 8% 3 6% 3 4 5% 4 6% 7% 41%	1890
	11th to 20th	Day	20% 7% 2 4 3 3 3 3 4 5% 44%	1975
	21st to end	Day	15% 9% 2 7% 5% 5% 4 4 5% 5% 39%	1730
March	1st to 10th	Day	19% 7% 2 6% 4 4 4 3 5% 6% 39%	4903
	11th to 20th	Day	10% 6% 2 5% 4 3 3 3 5% 7% 52%	5090
	21st to end	Day	15% 6% 2 5% 4 4 4 4 5% 7% 44%	5726
April	1st to 10th	Day	12% 5% 2 5% 4 3 4 3 5% 7% 50%	2520
	11th to 20th	Day	10% 6% 2 5% 4 4 4 4 5% 7% 48%	2494
	21st to end	Day	13% 6% 2 6% 4 5% 4 3 6% 8% 43%	2520
May	1st to 10th	Day	16% 6% 2 6% 4 4 5% 4 6% 8% 39%	7134
	11th to 20th	Day	15% 6% 2 6% 4 4 4 4 6% 8% 41%	7922
	21st to end	Day	19% 6% 2 5% 4 4 4 4 5% 7% 39%	9045
June	1st to 10th	Day	9% 6% 2 6% 4 5% 5% 5% 7% 10% 42%	2940
	11th to 20th	Day	11% 5% 2 6% 4 5% 5% 4 7% 10% 42%	2940
	21st to end	Day	7% 5% 2 6% 5% 5% 5% 4 8% 11% 41%	2940
July	1st to 10th	Day	7% 5% 2 6% 5% 5% 5% 5% 8% 12% 40%	6360
	11th to 20th	Day	12% 6% 3 9% 5% 6% 7% 5% 8% 12% 27%	6046
	21st to end	Day	7% 5% 2 7% 5% 6% 7% 6% 8% 11% 36%	6424
August	1st to 10th	Day	15% 8% 3 7% 5% 6% 6% 5% 8% 10% 27%	4234
	11th to 20th	Day	11% 5% 3 7% 6% 6% 7% 5% 7% 9% 34%	3864
	21st to end	Day	9% 4 2 5% 4 4 5% 4 7% 10% 47%	4312
September	1st to 10th	Day	13% 6% 2 6% 4 4 5% 4 6% 8% 42%	2400
	11th to 20th	Day	13% 6% 3 7% 4 5% 5% 4 6% 6% 41%	2400
	21st to end	Day	20% 8% 3 6% 4 5% 3 3 6% 6% 35%	2128
October	1st to 10th	Day	15% 6% 2 6% 4 4 4 3 4 6% 45%	2000
	11th to 20th	Day	16% 6% 2 5% 3 2 3 2 5% 5% 51%	2000
	21st to end	Day	13% 5% 2 5% 5% 3 4 3 4 5% 53%	2200
November	1st to 10th	Day	14% 6% 2 5% 3 3 4 2 5% 6% 52%	1960
	11th to 20th	Day	13% 6% 2 5% 3 3 3 3 4 7% 50%	1890
	21st to end	Day	14% 4 2 5% 4 4 3 3 6% 5% 51%	1780
December	1st to 10th	Day	11% 5% 2 5% 4 3 3 3 5% 6% 54%	2680
	11th to 20th	Day	19% 8% 2 4 3 2 3 3 3 5% 47%	3070
	21st to end	Day	13% 6% 2 5% 3 3 4 3 5% 7% 49%	4048
January	1st to 10th	Night	12% 6% 2 6% 4 4 4 3 5% 6% 49%	7956
	11th to 20th	Night	13% 6% 2 6% 3 3 3 2 3 4 55%	7680
	21st to end	Night	17% 6% 2 5% 3 3 3 3 4 5% 49%	8401
February	1st to 10th	Night	16% 8% 3 5% 4 3 4 3 5% 6% 43%	2730
	11th to 20th	Night	21% 7% 2 5% 3 3 3 4 5% 5% 42%	2530
	21st to end	Night	17% 8% 2 5% 3 3 3 3 5% 6% 45%	2076
March	1st to 10th	Night	19% 7% 2 6% 3 3 3 3 4 6% 45%	5165
	11th to 20th	Night	13% 6% 3 5% 4 4 3 3 4 6% 50%	5090
	21st to end	Night	14% 7% 3 5% 4 4 4 3 4 6% 47%	5448
April	1st to 10th	Night	13% 7% 3 6% 4 4 4 4 6% 7% 43%	2100
	11th to 20th	Night	12% 6% 2 5% 4 4 3 2 5% 8% 50%	2075
	21st to end	Night	14% 7% 2 5% 3 4 4 3 6% 7% 45%	2100
May	1st to 10th	Night	14% 6% 2 7% 5% 5% 5% 4 7% 9% 35%	5774
	11th to 20th	Night	17% 6% 2 5% 4 4 4 3 5% 7% 41%	4937
	21st to end	Night	21% 8% 3 7% 3 3 4 3 5% 7% 35%	5108
June	1st to 10th	Night	10% 5% 2 6% 5% 5% 5% 5% 7% 10% 40%	1680
	11th to 20th	Night	9% 6% 2 6% 4 5% 6% 5% 7% 11% 39%	1680
	21st to end	Night	8% 5% 2 7% 6% 4 5% 5% 7% 9% 44%	1680
July	1st to 10th	Night	10% 5% 2 6% 6% 6% 5% 5% 7% 10% 38%	3598
	11th to 20th	Night	11% 7% 3 7% 5% 6% 6% 5% 9% 12% 29%	3907
	21st to end	Night	10% 6% 3 7% 5% 5% 6% 5% 7% 9% 36%	4427
August	1st to 10th	Night	17% 8% 3 7% 6% 5% 5% 4 7% 8% 30%	2915
	11th to 20th	Night	9% 7% 2 7% 5% 5% 5% 4 7% 9% 41%	3150
	21st to end	Night	9% 5% 2 6% 4 4 4 4 6% 9% 48%	3586
September	1st to 10th	Night	11% 5% 2 5% 4 4 5% 3 7% 7% 46%	2000
	11th to 20th	Night	12% 5% 2 6% 4 4 4 4 6% 7% 45%	2000
	21st to end	Night	20% 8% 3 7% 4 4 4 4 5% 6% 35%	2265
October	1st to 10th	Night	14% 6% 2 6% 4 3 4 3 5% 6% 47%	2400
	11th to 20th	Night	14% 6% 2 6% 4 3 3 2 4 6% 50%	2400
	21st to end	Night	15% 5% 1 4 3 4 3 2 4 5% 53%	2640
November	1st to 10th	Night	13% 6% 2 6% 4 3 3 3 4 5% 50%	2556
	11th to 20th	Night	15% 7% 2 4 3 4 3 3 5% 5% 48%	2730
	21st to end	Night	12% 4 2 5% 4 4 4 4 4 6% 51%	2838
December	1st to 10th	Night	10% 5% 2 4 3 4 4 3 4 6% 54%	4720
	11th to 20th	Night	18% 7% 3 7% 4 4 4 3 5% 6% 39%	5345
	21st to end	Night	12% 7% 2 6% 3 3 3 3 5% 7% 48%	7150

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	26% 21% 8% 21% 16% 8%	4935
	11th to 20th	Day	26% 21% 3 15% 25% 10%	5280
	21st to end	Day	33% 23% 5% 24% 13% 2	5780
February	1st to 10th	Day	18% 59% 4 11% 6% 1	1890
	11th to 20th	Day	21% 58% 3 8% 8% 2	1984
	21st to end	Day	21% 58% 4 8% 6% 2	1730
March	1st to 10th	Day	37% 29% 6% 9% 13% 5%	4903
	11th to 20th	Day	22% 29% 6% 18% 18% 7%	5090
	21st to end	Day	29% 29% 9% 12% 16% 5%	5726
April	1st to 10th	Day	16% 59% 5% 10% 9% 2	2520
	11th to 20th	Day	14% 59% 5% 12% 8% 2	2494
	21st to end	Day	17% 60% 5% 11% 5% 2	2520
May	1st to 10th	Day	34% 26% 10% 17% 12% 1	7166
	11th to 20th	Day	32% 25% 10% 21% 12%	7926
	21st to end	Day	37% 24% 8% 15% 13% 3	9061
June	1st to 10th	Day	17% 60% 5% 9% 8% 1	2940
	11th to 20th	Day	14% 60% 8% 11% 7%	2940
	21st to end	Day	13% 58% 8% 13% 7%	2940
July	1st to 10th	Day	26% 32% 17% 14% 9% 2	6290
	11th to 20th	Day	39% 32% 18% 9% 2	5973
	21st to end	Day	27% 30% 11% 16% 15%	6240
August	1st to 10th	Day	35% 38% 12% 12% 3	4221
	11th to 20th	Day	26% 40% 10% 16% 7%	3900
	21st to end	Day	16% 38% 10% 21% 15% 1	4312
September	1st to 10th	Day	18% 58% 7% 10% 6% 1	2400
	11th to 20th	Day	20% 57% 4 10% 7% 2	2400
	21st to end	Day	26% 56% 4 10% 2 1	2128
October	1st to 10th	Day	20% 39% 6% 14% 18% 3	3260
	11th to 20th	Day	13% 36% 3 13% 29% 7%	3240
	21st to end	Day	9% 35% 6% 20% 20% 10%	3538
November	1st to 10th	Day	18% 53% 4 13% 9% 2	1960
	11th to 20th	Day	17% 53% 4 10% 12% 3	1890
	21st to end	Day	17% 53% 3 14% 11% 2	1780
December	1st to 10th	Day	22% 34% 5% 21% 13% 5%	2680
	11th to 20th	Day	30% 31% 9% 14% 13% 4	3066
	21st to end	Day	26% 27% 9% 23% 13% 1	4048
January	1st to 10th	Night	29% 21% 8% 18% 18% 6%	7957
	11th to 20th	Night	26% 20% 2 19% 24% 8%	7680
	21st to end	Night	31% 22% 4 23% 15% 4	8401
February	1st to 10th	Night	18% 58% 6% 10% 7% 1	2730
	11th to 20th	Night	20% 58% 3 9% 8% 2	2532
	21st to end	Night	17% 58% 4 10% 7% 3	2076
March	1st to 10th	Night	32% 29% 4 14% 14% 7%	5165
	11th to 20th	Night	24% 29% 5% 15% 19% 8%	5090
	21st to end	Night	29% 29% 5% 18% 14% 5%	5448
April	1st to 10th	Night	18% 59% 4 8% 10% 1	2100
	11th to 20th	Night	15% 59% 5% 12% 8% 2	2075
	21st to end	Night	17% 59% 5% 11% 7% 1	2100
May	1st to 10th	Night	35% 26% 12% 19% 8%	5804
	11th to 20th	Night	33% 24% 10% 22% 10%	4938
	21st to end	Night	41% 24% 8% 14% 12% 1	5115
June	1st to 10th	Night	17% 59% 5% 8% 9% 1	1680
	11th to 20th	Night	15% 60% 7% 10% 8% 1	1680
	21st to end	Night	13% 59% 6% 12% 8% 2	1680
July	1st to 10th	Night	31% 34% 13% 13% 9% 1	3560
	11th to 20th	Night	36% 33% 18% 11% 1	3860
	21st to end	Night	32% 30% 9% 17% 12%	4297
August	1st to 10th	Night	37% 38% 10% 13% 2	2904
	11th to 20th	Night	22% 40% 13% 17% 8%	3180
	21st to end	Night	18% 37% 5% 19% 20% 1	3586
September	1st to 10th	Night	16% 58% 9% 10% 5% 2	2000
	11th to 20th	Night	18% 57% 4 11% 8% 1	2000
	21st to end	Night	26% 58% 5% 8% 3	2265
October	1st to 10th	Night	22% 37% 8% 14% 15% 3	3920
	11th to 20th	Night	12% 36% 4 15% 24% 9%	3899
	21st to end	Night	9% 35% 3 24% 18% 11%	4252
November	1st to 10th	Night	20% 53% 4 11% 10% 2	2556
	11th to 20th	Night	17% 54% 4 10% 10% 6%	2730
	21st to end	Night	15% 54% 4 13% 12% 2	2838
December	1st to 10th	Night	19% 35% 5% 20% 18% 3	4720
	11th to 20th	Night	34% 32% 7% 12% 10% 5%	5348
	21st to end	Night	28% 26% 10% 23% 12% 1	7150

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	28% 28% 32% 10% 2	269
	11th to 20th	Day	27% 33% 29% 10% 1	330
	21st to end	Day	23% 29% 39% 8% 1	363
February	1st to 10th	Day	24% 29% 36% 8% 3	330
	11th to 20th	Day	33% 26% 30% 10% 1	463
	21st to end	Day	30% 21% 33% 13% 3	446
March	1st to 10th	Day	23% 27% 33% 14% 4	540
	11th to 20th	Day	26% 25% 31% 13% 4 1	540
	21st to end	Day	22% 24% 36% 13% 4 1	594
April	1st to 10th	Day	22% 25% 34% 14% 4 1	540
	11th to 20th	Day	15% 19% 38% 20% 5% 3	532
	21st to end	Day	19% 15% 40% 20% 5% 1	540
May	1st to 10th	Day	19% 20% 38% 17% 5% 1	543
	11th to 20th	Day	20% 13% 36% 22% 8% 1	567
	21st to end	Day	23% 9% 29% 25% 12% 3	617
June	1st to 10th	Day	13% 9% 33% 29% 14% 2	570
	11th to 20th	Day	13% 9% 28% 32% 14% 4	570
	21st to end	Day	10% 6% 28% 35% 17% 4	570
July	1st to 10th	Day	9% 3 23% 37% 23% 4	525
	11th to 20th	Day	6% 3 21% 39% 24% 6%	524
	21st to end	Day	9% 2 26% 34% 20% 7%	576
August	1st to 10th	Day	12% 6% 26% 33% 19% 5%	526
	11th to 20th	Day	12% 5% 20% 37% 20% 6%	519
	21st to end	Day	10% 4 25% 29% 23% 9%	583
September	1st to 10th	Day	15% 4 26% 28% 17% 10%	530
	11th to 20th	Day	15% 7% 24% 29% 16% 8%	530
	21st to end	Day	28% 11% 25% 22% 10% 4	530
October	1st to 10th	Day	19% 8% 25% 26% 15% 8%	530
	11th to 20th	Day	19% 15% 26% 28% 11% 2	530
	21st to end	Day	17% 15% 33% 21% 10% 4	583
November	1st to 10th	Day	18% 13% 32% 23% 11% 3	483
	11th to 20th	Day	20% 19% 32% 21% 8% 1	430
	21st to end	Day	21% 19% 30% 20% 10% 1	320
December	1st to 10th	Day	25% 19% 39% 13% 4	220
	11th to 20th	Day	26% 20% 31% 19% 4	220
	21st to end	Day	22% 25% 31% 14% 7%	242
January	1st to 10th	Night	19% 24% 35% 20% 3	840
	11th to 20th	Night	22% 21% 32% 21% 5%	840
	21st to end	Night	22% 19% 35% 22% 2	924
February	1st to 10th	Night	21% 17% 40% 19% 3	840
	11th to 20th	Night	28% 23% 34% 13% 2	823
	21st to end	Night	24% 21% 35% 18% 3	692
March	1st to 10th	Night	21% 17% 35% 23% 4	840
	11th to 20th	Night	24% 18% 33% 21% 4 1	840
	21st to end	Night	19% 17% 41% 19% 4	924
April	1st to 10th	Night	18% 21% 40% 18% 3	840
	11th to 20th	Night	15% 15% 41% 23% 6% 1	831
	21st to end	Night	18% 12% 35% 29% 6%	840
May	1st to 10th	Night	17% 15% 37% 25% 5% 1	819
	11th to 20th	Night	16% 8% 32% 34% 9% 1	519
	21st to end	Night	18% 4 22% 37% 16% 2	455
June	1st to 10th	Night	11% 3 25% 43% 16% 2	420
	11th to 20th	Night	10% 5% 25% 41% 16% 2	420
	21st to end	Night	7% 4 23% 43% 20% 2	420
July	1st to 10th	Night	11% 3 20% 42% 23% 1	390
	11th to 20th	Night	6% 2 15% 45% 29% 4	514
	21st to end	Night	7% 3 21% 40% 26% 3	657
August	1st to 10th	Night	10% 3 16% 41% 26% 4	597
	11th to 20th	Night	12% 3 16% 41% 25% 3	755
	21st to end	Night	9% 4 17% 36% 29% 5%	880
September	1st to 10th	Night	15% 4 17% 38% 23% 3	800
	11th to 20th	Night	15% 4 17% 35% 25% 4	800
	21st to end	Night	25% 7% 22% 28% 17% 2	800
October	1st to 10th	Night	17% 7% 21% 31% 20% 5%	800
	11th to 20th	Night	20% 11% 27% 28% 13% 2	800
	21st to end	Night	18% 11% 29% 26% 13% 2	880
November	1st to 10th	Night	17% 10% 28% 29% 14% 2	820
	11th to 20th	Night	19% 15% 31% 27% 7%	840
	21st to end	Night	14% 17% 29% 30% 8% 1	840
December	1st to 10th	Night	22% 14% 36% 19% 8% 1	840
	11th to 20th	Night	19% 13% 40% 23% 5%	840
	21st to end	Night	19% 17% 30% 29% 5%	924

Page generated at 2026-06-28 02:10:49. Version ac07

Copyright © 2026 Attilla Danko.