Lake of the Woods
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lake of the Woods clear sky chart from 2005-11-06 to 2026-08-30.

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% 9% 3 7% 4 3 4 3 4 6% 53%	153184
	Night	5% 9% 4 8% 5% 4 4 3 4 6% 48%	146433
Transparency	Day	32% 5% 7% 21% 22% 13%	148032
	Night	37% 5% 8% 20% 20% 11%	142579
Seeing	Day	19% 16% 27% 22% 12% 3	17189
	Night	18% 10% 18% 31% 20% 3	26207

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	9% 22% 8% 12% 7% 5% 5% 4 4 5% 19%	4722
	11th to 20th	Day	7% 11% 4 6% 3 2 3 2 4 4 53%	4898
	21st to end	Day	7% 13% 3 7% 4 5% 6% 4 5% 6% 40%	5843
February	1st to 10th	Day	8% 15% 5% 11% 5% 4 5% 4 6% 7% 29%	1890
	11th to 20th	Day	5% 17% 7% 12% 6% 5% 4 4 5% 6% 29%	1845
	21st to end	Day	8% 17% 7% 11% 7% 4 5% 2 4 6% 28%	1720
March	1st to 10th	Day	6% 19% 7% 14% 5% 3 4 2 4 6% 31%	4841
	11th to 20th	Day	5% 17% 6% 11% 6% 5% 4 3 4 5% 35%	5110
	21st to end	Day	5% 22% 6% 14% 7% 5% 4 3 4 6% 24%	5739
April	1st to 10th	Day	9% 18% 5% 11% 5% 5% 5% 3 4 6% 29%	2520
	11th to 20th	Day	9% 15% 5% 9% 5% 4 4 3 4 7% 34%	2489
	21st to end	Day	5% 13% 3 8% 5% 4 4 4 7% 7% 39%	2587
May	1st to 10th	Day	5% 8% 2 5% 3 4 4 4 5% 7% 53%	7852
	11th to 20th	Day	3 6% 2 5% 3 4 4 3 5% 7% 57%	8160
	21st to end	Day	6% 6% 2 4 3 3 3 3 5% 8% 56%	8992
June	1st to 10th	Day	9% 8% 2 5% 4 4 4 3 6% 8% 46%	2940
	11th to 20th	Day	3 5% 2 5% 4 4 4 3 4 7% 59%	2940
	21st to end	Day	4 4 1 4 3 2 3 2 4 6% 68%	2940
July	1st to 10th	Day	1 1 2 1 2 2 2 3 4 81%	8219
	11th to 20th	Day	2 2 1 3 2 2 3 2 3 4 76%	8220
	21st to end	Day	1 1 1 2 2 2 2 2 3 4 80%	8650
August	1st to 10th	Day	2 2 1 2 2 2 3 3 5% 6% 72%	5907
	11th to 20th	Day	2 1 1 2 2 2 2 2 4 5% 78%	5894
	21st to end	Day	2 3 1 4 3 2 3 3 4 5% 70%	6093
September	1st to 10th	Day	1 1 1 3 2 2 3 2 4 6% 76%	2400
	11th to 20th	Day	4 4 2 5% 3 3 4 3 5% 6% 60%	2400
	21st to end	Day	4 5% 2 6% 2 3 3 3 4 6% 62%	2118
October	1st to 10th	Day	4 4 2 3 3 3 3 2 4 5% 69%	3280
	11th to 20th	Day	5% 6% 2 7% 4 4 5% 4 6% 8% 48%	3261
	21st to end	Day	7% 11% 4 10% 5% 4 5% 3 5% 7% 40%	3558
November	1st to 10th	Day	11% 13% 4 9% 5% 5% 5% 3 5% 7% 33%	1859
	11th to 20th	Day	9% 15% 5% 11% 6% 5% 5% 4 6% 7% 26%	1717
	21st to end	Day	6% 15% 4 10% 4 5% 5% 3 7% 6% 34%	1680
December	1st to 10th	Day	5% 9% 3 8% 5% 4 4 4 5% 8% 46%	2700
	11th to 20th	Day	11% 19% 6% 14% 6% 4 5% 4 5% 7% 19%	3108
	21st to end	Day	12% 17% 6% 14% 8% 6% 6% 4 5% 6% 15%	4092
January	1st to 10th	Night	7% 18% 6% 16% 10% 7% 5% 4 5% 5% 18%	8172
	11th to 20th	Night	5% 11% 4 8% 3 3 3 2 3 5% 54%	8066
	21st to end	Night	7% 12% 4 10% 6% 6% 5% 4 4 5% 36%	8371
February	1st to 10th	Night	8% 13% 5% 11% 6% 5% 5% 4 5% 7% 32%	2730
	11th to 20th	Night	7% 15% 5% 11% 7% 6% 6% 4 4 6% 30%	2662
	21st to end	Night	6% 14% 5% 13% 7% 6% 6% 4 5% 6% 30%	2084
March	1st to 10th	Night	4 14% 8% 14% 7% 5% 5% 3 6% 7% 27%	5271
	11th to 20th	Night	4 13% 6% 13% 7% 6% 4 3 4 5% 36%	5110
	21st to end	Night	4 14% 7% 14% 10% 8% 6% 4 5% 6% 23%	5477
April	1st to 10th	Night	10% 14% 4 10% 6% 4 6% 4 6% 7% 29%	2100
	11th to 20th	Night	5% 12% 5% 11% 6% 6% 4 3 4 7% 38%	2079
	21st to end	Night	6% 12% 5% 8% 5% 6% 4 4 6% 9% 37%	2030
May	1st to 10th	Night	4 7% 4 6% 4 3 3 2 4 5% 57%	5083
	11th to 20th	Night	2 6% 3 5% 3 5% 5% 3 6% 7% 55%	4700
	21st to end	Night	5% 6% 2 4 3 3 4 3 5% 6% 60%	5181
June	1st to 10th	Night	9% 8% 3 6% 5% 3 4 4 5% 7% 46%	1680
	11th to 20th	Night	2 4 2 5% 5% 4 4 4 5% 7% 59%	1680
	21st to end	Night	4 4 1 3 2 3 2 2 4 5% 71%	1680
July	1st to 10th	Night	1 1 1 2 2 2 2 2 2 3 81%	4740
	11th to 20th	Night	2 2 1 3 3 2 2 1 3 3 78%	4740
	21st to end	Night	2 2 1 2 2 1 2 2 3 4 80%	5424
August	1st to 10th	Night	2 1 1 2 2 2 2 3 5% 7% 74%	4125
	11th to 20th	Night	1 1 1 2 2 3 3 3 3 4 78%	4174
	21st to end	Night	4 3 1 3 2 2 2 2 4 5% 72%	5105
September	1st to 10th	Night	2 1 2 2 2 3 2 4 5% 78%	2000
	11th to 20th	Night	3 5% 2 4 3 3 3 3 5% 6% 64%	2000
	21st to end	Night	6% 4 2 4 2 2 2 2 3 6% 65%	2278
October	1st to 10th	Night	3 3 1 4 4 3 2 2 3 4 71%	3920
	11th to 20th	Night	5% 6% 2 7% 4 4 3 3 4 7% 54%	3897
	21st to end	Night	5% 6% 3 10% 7% 6% 6% 4 6% 8% 40%	4253
November	1st to 10th	Night	12% 11% 4 9% 7% 6% 5% 3 4 6% 34%	2658
	11th to 20th	Night	10% 13% 5% 10% 8% 6% 6% 4 6% 8% 24%	2901
	21st to end	Night	6% 14% 4 9% 6% 5% 5% 3 5% 6% 37%	2940
December	1st to 10th	Night	6% 8% 3 6% 4 4 5% 3 5% 7% 48%	4700
	11th to 20th	Night	9% 19% 7% 15% 7% 6% 5% 4 4 6% 20%	5316
	21st to end	Night	13% 16% 7% 13% 7% 5% 5% 3 4 5% 22%	7106

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	65% 5% 9% 14% 6% 1	4723
	11th to 20th	Day	36% 2 4 14% 23% 21%	4898
	21st to end	Day	43% 4 8% 13% 16% 15%	5843
February	1st to 10th	Day	49% 9% 11% 17% 12% 3	1890
	11th to 20th	Day	53% 6% 10% 16% 12% 3	1854
	21st to end	Day	54% 7% 8% 16% 11% 4	1720
March	1st to 10th	Day	52% 5% 7% 20% 13% 3	4841
	11th to 20th	Day	50% 4 10% 19% 16% 1	5110
	21st to end	Day	58% 8% 10% 19% 4 1	5739
April	1st to 10th	Day	53% 7% 10% 18% 9% 2	2520
	11th to 20th	Day	47% 6% 11% 19% 13% 3	2492
	21st to end	Day	39% 8% 12% 25% 14% 2	2587
May	1st to 10th	Day	27% 5% 7% 28% 27% 5%	7852
	11th to 20th	Day	23% 4 11% 26% 31% 5%	8163
	21st to end	Day	25% 5% 11% 41% 17% 1	8994
June	1st to 10th	Day	32% 7% 12% 28% 19% 2	2940
	11th to 20th	Day	21% 7% 9% 32% 24% 7%	2940
	21st to end	Day	18% 3 7% 27% 32% 13%	2940
July	1st to 10th	Day	10% 2 2 21% 31% 34%	8151
	11th to 20th	Day	14% 3 2 12% 25% 44%	8145
	21st to end	Day	10% 3 2 22% 33% 30%	8456
August	1st to 10th	Day	16% 3 3 15% 27% 36%	4336
	11th to 20th	Day	11% 3 4 24% 41% 17%	4305
	21st to end	Day	15% 2 4 26% 33% 21%	4420
September	1st to 10th	Day	11% 4 3 19% 32% 30%	2400
	11th to 20th	Day	23% 5% 6% 23% 30% 13%	2400
	21st to end	Day	22% 5% 7% 22% 28% 16%	2118
October	1st to 10th	Day	19% 3 8% 15% 32% 23%	3280
	11th to 20th	Day	29% 5% 15% 29% 17% 5%	3261
	21st to end	Day	41% 4 8% 22% 20% 5%	3558
November	1st to 10th	Day	46% 6% 10% 19% 14% 3	1859
	11th to 20th	Day	54% 7% 13% 13% 10% 4	1717
	21st to end	Day	47% 6% 10% 16% 16% 5%	1680
December	1st to 10th	Day	35% 5% 7% 20% 23% 10%	2700
	11th to 20th	Day	61% 5% 13% 14% 6% 1	3108
	21st to end	Day	66% 6% 8% 13% 6% 1	4092
January	1st to 10th	Night	64% 6% 10% 12% 7% 1	8172
	11th to 20th	Night	34% 4 4 13% 21% 24%	8066
	21st to end	Night	49% 3 7% 10% 16% 16%	8371
February	1st to 10th	Night	48% 7% 10% 17% 15% 3	2730
	11th to 20th	Night	51% 7% 9% 17% 12% 3	2664
	21st to end	Night	50% 9% 12% 15% 12% 4	2084
March	1st to 10th	Night	51% 8% 8% 20% 10% 4	5271
	11th to 20th	Night	48% 4 10% 20% 16% 1	5110
	21st to end	Night	56% 9% 13% 16% 7% 1	5477
April	1st to 10th	Night	49% 8% 14% 19% 9% 1	2100
	11th to 20th	Night	42% 8% 13% 19% 14% 3	2079
	21st to end	Night	38% 10% 14% 21% 15% 2	2030
May	1st to 10th	Night	29% 4 7% 27% 29% 5%	5081
	11th to 20th	Night	23% 4 14% 27% 29% 2	4700
	21st to end	Night	20% 6% 13% 45% 16%	5182
June	1st to 10th	Night	35% 6% 13% 25% 18% 2	1680
	11th to 20th	Night	21% 7% 10% 31% 25% 7%	1680
	21st to end	Night	16% 3 7% 30% 33% 10%	1680
July	1st to 10th	Night	11% 2 4 20% 31% 33%	4700
	11th to 20th	Night	14% 2 1 12% 30% 40%	4692
	21st to end	Night	12% 2 2 25% 32% 27%	5306
August	1st to 10th	Night	13% 3 4 17% 31% 31%	3019
	11th to 20th	Night	10% 3 3 30% 36% 19%	3038
	21st to end	Night	14% 2 6% 29% 30% 19%	3698
September	1st to 10th	Night	8% 4 3 19% 35% 29%	2000
	11th to 20th	Night	20% 6% 8% 21% 30% 16%	2000
	21st to end	Night	20% 5% 7% 25% 24% 19%	2278
October	1st to 10th	Night	18% 4 6% 18% 32% 23%	3920
	11th to 20th	Night	29% 5% 11% 30% 19% 6%	3897
	21st to end	Night	37% 5% 10% 23% 19% 6%	4253
November	1st to 10th	Night	46% 8% 10% 16% 14% 5%	2658
	11th to 20th	Night	53% 9% 10% 13% 12% 4	2901
	21st to end	Night	45% 6% 9% 16% 16% 8%	2940
December	1st to 10th	Night	33% 4 8% 17% 29% 10%	4700
	11th to 20th	Night	63% 6% 8% 14% 7% 1	5316
	21st to end	Night	62% 6% 10% 12% 9% 1	7106

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	38% 21% 22% 14% 5%	220
	11th to 20th	Day	29% 17% 22% 19% 10% 3	274
	21st to end	Day	26% 18% 22% 22% 11% 1	473
February	1st to 10th	Day	29% 20% 27% 19% 6%	430
	11th to 20th	Day	32% 22% 22% 16% 7%	425
	21st to end	Day	32% 19% 26% 17% 7%	441
March	1st to 10th	Day	33% 21% 26% 16% 4 1	540
	11th to 20th	Day	28% 19% 26% 17% 9% 1	540
	21st to end	Day	34% 23% 25% 14% 4 1	594
April	1st to 10th	Day	26% 23% 24% 19% 7% 2	540
	11th to 20th	Day	29% 20% 27% 15% 6% 3	532
	21st to end	Day	21% 23% 27% 18% 8% 2	540
May	1st to 10th	Day	20% 19% 31% 20% 8% 2	543
	11th to 20th	Day	26% 18% 24% 18% 10% 3	568
	21st to end	Day	20% 15% 26% 22% 12% 4	617
June	1st to 10th	Day	18% 17% 28% 21% 14% 3	570
	11th to 20th	Day	15% 20% 31% 21% 12% 1	570
	21st to end	Day	7% 14% 31% 26% 17% 5%	570
July	1st to 10th	Day	6% 13% 34% 27% 15% 5%	566
	11th to 20th	Day	4 12% 34% 27% 16% 6%	564
	21st to end	Day	4 8% 35% 28% 19% 7%	619
August	1st to 10th	Day	2 10% 31% 28% 21% 8%	567
	11th to 20th	Day	5% 11% 29% 27% 20% 8%	557
	21st to end	Day	6% 11% 28% 29% 20% 5%	620
September	1st to 10th	Day	2 12% 29% 31% 19% 5%	530
	11th to 20th	Day	12% 11% 28% 28% 18% 3	530
	21st to end	Day	11% 15% 27% 30% 15% 2	530
October	1st to 10th	Day	16% 16% 27% 23% 16% 2	530
	11th to 20th	Day	18% 13% 23% 26% 17% 2	530
	21st to end	Day	23% 14% 28% 19% 14% 2	583
November	1st to 10th	Day	28% 13% 20% 26% 13%	335
	11th to 20th	Day	27% 10% 30% 19% 12% 3	239
	21st to end	Day	23% 19% 21% 23% 14% 1	220
December	1st to 10th	Day	28% 12% 27% 22% 7% 5%	220
	11th to 20th	Day	36% 15% 21% 14% 13% 1	220
	21st to end	Day	33% 19% 19% 20% 6% 2	242
January	1st to 10th	Night	31% 14% 20% 21% 11% 3	840
	11th to 20th	Night	23% 13% 18% 26% 15% 3	840
	21st to end	Night	24% 11% 18% 27% 17% 4	924
February	1st to 10th	Night	23% 12% 23% 29% 11% 2	840
	11th to 20th	Night	22% 17% 20% 26% 14% 1	824
	21st to end	Night	23% 15% 22% 29% 10% 1	692
March	1st to 10th	Night	24% 17% 21% 25% 11% 2	840
	11th to 20th	Night	22% 14% 17% 29% 16% 2	840
	21st to end	Night	25% 16% 23% 24% 11% 1	924
April	1st to 10th	Night	24% 13% 20% 26% 14% 2	840
	11th to 20th	Night	19% 17% 23% 24% 15% 3	831
	21st to end	Night	18% 13% 21% 30% 17% 2	770
May	1st to 10th	Night	13% 11% 24% 31% 20% 2	546
	11th to 20th	Night	13% 10% 21% 32% 21% 2	414
	21st to end	Night	15% 9% 18% 31% 24% 2	455
June	1st to 10th	Night	17% 6% 20% 32% 22% 3	420
	11th to 20th	Night	8% 6% 22% 41% 22% 2	420
	21st to end	Night	8% 3 15% 44% 29% 1	420
July	1st to 10th	Night	3 2 14% 46% 32% 2	410
	11th to 20th	Night	2 2 19% 49% 27% 1	408
	21st to end	Night	2 2 12% 42% 38% 5%	552
August	1st to 10th	Night	3 1 10% 42% 38% 7%	627
	11th to 20th	Night	3 2 11% 35% 42% 8%	630
	21st to end	Night	4 4 19% 41% 29% 3	916
September	1st to 10th	Night	3 4 17% 39% 32% 5%	800
	11th to 20th	Night	7% 5% 16% 33% 33% 6%	800
	21st to end	Night	11% 6% 13% 35% 29% 5%	800
October	1st to 10th	Night	9% 9% 19% 33% 27% 4	800
	11th to 20th	Night	15% 9% 13% 33% 26% 5%	800
	21st to end	Night	18% 9% 18% 30% 19% 6%	880
November	1st to 10th	Night	24% 10% 20% 26% 16% 4	820
	11th to 20th	Night	27% 10% 18% 28% 15% 2	840
	21st to end	Night	21% 13% 18% 27% 17% 3	840
December	1st to 10th	Night	23% 10% 18% 30% 15% 3	840
	11th to 20th	Night	28% 12% 20% 26% 13% 2	840
	21st to end	Night	34% 15% 19% 24% 7% 1	924

Page generated at 2026-08-27 01:07:15. Version ac07

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