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 2024-11-01.

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	6% 10% 3 7% 4 3 3 3 4 5% 51%	101426
	Night	6% 11% 4 8% 5% 4 4 3 4 6% 45%	97709
Transparency	Day	34% 5% 8% 20% 20% 13%	101174
	Night	38% 7% 9% 19% 18% 10%	97550
Seeing	Day	18% 16% 27% 23% 13% 3	14877
	Night	17% 10% 18% 31% 21% 3	23934

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% 23% 11% 11% 7% 6% 5% 4 4 4 19%	2539
	11th to 20th	Day	14% 21% 8% 12% 5% 3 4 2 4 4 22%	2614
	21st to end	Day	13% 22% 4 8% 4 5% 5% 3 5% 6% 26%	3146
February	1st to 10th	Day	8% 15% 5% 12% 5% 4 5% 4 6% 7% 28%	1710
	11th to 20th	Day	6% 17% 7% 11% 5% 5% 4 4 5% 6% 31%	1665
	21st to end	Day	8% 18% 7% 11% 7% 4 5% 2 4 6% 27%	1560
March	1st to 10th	Day	6% 22% 8% 16% 5% 4 3 2 3 4 26%	3291
	11th to 20th	Day	6% 15% 3 6% 4 3 3 2 4 4 48%	3490
	21st to end	Day	6% 24% 6% 12% 7% 6% 5% 3 4 5% 22%	3915
April	1st to 10th	Day	10% 19% 6% 11% 5% 4 4 3 4 5% 29%	2280
	11th to 20th	Day	9% 16% 5% 9% 5% 4 4 3 4 7% 32%	2249
	21st to end	Day	5% 14% 4 8% 5% 4 4 4 7% 7% 38%	2341
May	1st to 10th	Day	7% 14% 3 7% 4 4 3 3 4 5% 46%	4233
	11th to 20th	Day	5% 6% 2 5% 2 2 3 3 4 6% 62%	4377
	21st to end	Day	6% 7% 2 5% 4 4 4 4 5% 8% 52%	4813
June	1st to 10th	Day	10% 8% 2 6% 4 4 5% 3 6% 9% 43%	2660
	11th to 20th	Day	4 5% 2 5% 4 4 4 4 4 7% 58%	2660
	21st to end	Day	4 4 1 4 3 2 3 2 4 5% 69%	2660
July	1st to 10th	Day	1 1 1 1 1 1 1 2 3 87%	4420
	11th to 20th	Day	2 2 1 2 2 2 3 2 3 3 78%	4420
	21st to end	Day	1 1 1 1 1 2 2 2 3 86%	4648
August	1st to 10th	Day	3 3 1 3 2 2 2 3 4 4 72%	4091
	11th to 20th	Day	2 1 2 2 2 2 2 4 5% 77%	4007
	21st to end	Day	2 3 1 4 2 2 2 2 2 3 77%	4180
September	1st to 10th	Day	1 1 1 3 2 2 3 2 3 6% 77%	2280
	11th to 20th	Day	4 4 2 5% 3 3 4 3 5% 6% 59%	2280
	21st to end	Day	4 5% 2 6% 2 3 3 3 4 6% 61%	2012
October	1st to 10th	Day	7% 6% 2 5% 4 4 3 3 4 5% 58%	1900
	11th to 20th	Day	8% 7% 2 6% 4 3 5% 3 5% 7% 49%	1900
	21st to end	Day	10% 9% 3 9% 5% 3 4 2 4 5% 46%	2090
November	1st to 10th	Day	12% 14% 5% 8% 5% 5% 5% 3 4 7% 33%	1679
	11th to 20th	Day	9% 15% 5% 10% 6% 5% 5% 4 6% 8% 28%	1554
	21st to end	Day	6% 16% 4 10% 4 4 5% 4 7% 7% 32%	1520
December	1st to 10th	Day	7% 14% 4 11% 6% 5% 4 4 5% 7% 33%	1520
	11th to 20th	Day	14% 17% 6% 10% 6% 4 5% 3 5% 8% 22%	1928
	21st to end	Day	12% 15% 6% 12% 7% 6% 5% 4 6% 7% 20%	2794
January	1st to 10th	Night	7% 22% 7% 13% 7% 6% 5% 4 5% 5% 18%	4406
	11th to 20th	Night	9% 19% 7% 14% 6% 5% 4 2 4 4 26%	4344
	21st to end	Night	13% 21% 6% 11% 6% 5% 4 3 4 5% 22%	4521
February	1st to 10th	Night	8% 13% 4 11% 6% 5% 5% 4 5% 7% 32%	2470
	11th to 20th	Night	7% 15% 5% 10% 7% 5% 6% 4 4 5% 31%	2402
	21st to end	Night	5% 14% 5% 13% 7% 6% 6% 4 5% 6% 30%	1892
March	1st to 10th	Night	4 17% 8% 16% 7% 5% 4 3 5% 6% 23%	3581
	11th to 20th	Night	5% 14% 5% 7% 5% 4 3 3 3 4 47%	3490
	21st to end	Night	6% 15% 8% 14% 7% 7% 6% 5% 5% 5% 22%	3737
April	1st to 10th	Night	10% 15% 4 10% 6% 4 5% 4 5% 7% 28%	1900
	11th to 20th	Night	5% 13% 5% 11% 6% 5% 4 3 4 6% 37%	1879
	21st to end	Night	5% 12% 5% 8% 5% 6% 4 4 6% 9% 35%	1837
May	1st to 10th	Night	6% 12% 7% 7% 4 3 3 2 5% 5% 47%	2732
	11th to 20th	Night	4 4 1 5% 3 4 3 3 4 5% 65%	2516
	21st to end	Night	4 8% 2 5% 3 4 5% 4 6% 7% 53%	2762
June	1st to 10th	Night	10% 9% 3 6% 5% 3 4 4 6% 8% 44%	1520
	11th to 20th	Night	3 4 2 5% 5% 4 4 4 5% 8% 58%	1520
	21st to end	Night	4 3 1 3 2 3 2 2 3 5% 72%	1520
July	1st to 10th	Night	1 1 1 1 1 1 2 2 3 86%	2540
	11th to 20th	Night	2 2 3 3 2 2 2 3 4 78%	2540
	21st to end	Night	1 1 2 2 2 2 2 3 3 82%	2906
August	1st to 10th	Night	2 2 1 3 2 2 2 2 5% 5% 74%	2848
	11th to 20th	Night	1 2 1 2 2 2 2 2 3 4 80%	2830
	21st to end	Night	5% 3 1 3 1 2 1 1 2 3 78%	3498
September	1st to 10th	Night	2 1 2 1 2 2 2 4 5% 80%	1900
	11th to 20th	Night	3 4 2 4 3 3 3 3 5% 6% 64%	1900
	21st to end	Night	6% 4 2 4 2 2 2 2 3 6% 65%	2164
October	1st to 10th	Night	5% 5% 2 5% 4 4 3 3 4 6% 60%	2280
	11th to 20th	Night	7% 7% 2 6% 4 5% 3 3 4 7% 52%	2280
	21st to end	Night	7% 7% 3 9% 6% 5% 4 3 5% 7% 43%	2508
November	1st to 10th	Night	12% 12% 4 8% 7% 5% 5% 3 4 6% 34%	2404
	11th to 20th	Night	10% 12% 5% 9% 8% 6% 6% 4 7% 8% 26%	2624
	21st to end	Night	7% 14% 4 10% 6% 5% 5% 3 5% 6% 36%	2660
December	1st to 10th	Night	10% 12% 5% 9% 5% 4 5% 4 6% 7% 33%	2660
	11th to 20th	Night	12% 19% 6% 11% 5% 5% 4 4 5% 7% 22%	3276
	21st to end	Night	10% 17% 5% 11% 7% 6% 5% 3 4 5% 27%	4862

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	64% 7% 9% 14% 5% 1	2539
	11th to 20th	Day	66% 4 6% 13% 7% 4	2614
	21st to end	Day	58% 6% 11% 15% 7% 3	3146
February	1st to 10th	Day	49% 9% 12% 17% 11% 2	1710
	11th to 20th	Day	51% 6% 10% 17% 13% 3	1674
	21st to end	Day	56% 7% 8% 15% 12% 3	1560
March	1st to 10th	Day	60% 6% 7% 14% 12% 1	3291
	11th to 20th	Day	38% 5% 10% 22% 23% 1	3490
	21st to end	Day	59% 9% 9% 18% 5% 1	3915
April	1st to 10th	Day	55% 7% 10% 16% 10% 3	2280
	11th to 20th	Day	48% 7% 12% 19% 11% 4	2252
	21st to end	Day	39% 9% 13% 25% 13% 2	2341
May	1st to 10th	Day	34% 8% 9% 26% 22% 1	4233
	11th to 20th	Day	22% 5% 7% 22% 37% 7%	4380
	21st to end	Day	27% 6% 15% 38% 12% 1	4814
June	1st to 10th	Day	34% 8% 13% 27% 17% 1	2660
	11th to 20th	Day	22% 8% 9% 33% 22% 6%	2660
	21st to end	Day	18% 3 6% 27% 32% 13%	2660
July	1st to 10th	Day	7% 2 4 12% 19% 56%	4351
	11th to 20th	Day	12% 3 3 11% 21% 49%	4345
	21st to end	Day	7% 2 2 15% 38% 36%	4501
August	1st to 10th	Day	16% 3 3 14% 28% 35%	4076
	11th to 20th	Day	11% 3 4 24% 41% 18%	4046
	21st to end	Day	14% 2 4 27% 32% 21%	4179
September	1st to 10th	Day	10% 3 3 18% 33% 32%	2280
	11th to 20th	Day	22% 5% 7% 23% 30% 14%	2280
	21st to end	Day	22% 5% 7% 23% 27% 15%	2012
October	1st to 10th	Day	27% 5% 9% 16% 28% 14%	1900
	11th to 20th	Day	32% 6% 11% 22% 21% 8%	1900
	21st to end	Day	39% 5% 9% 18% 20% 8%	2090
November	1st to 10th	Day	47% 7% 9% 19% 15% 3	1679
	11th to 20th	Day	51% 8% 13% 13% 11% 4	1554
	21st to end	Day	48% 6% 10% 15% 15% 6%	1520
December	1st to 10th	Day	49% 6% 10% 19% 14% 3	1520
	11th to 20th	Day	59% 5% 14% 14% 7% 2	1928
	21st to end	Day	61% 8% 9% 14% 7% 1	2794
January	1st to 10th	Night	63% 8% 10% 12% 6% 1	4406
	11th to 20th	Night	60% 7% 7% 13% 9% 5%	4344
	21st to end	Night	64% 5% 7% 12% 10% 2	4521
February	1st to 10th	Night	48% 7% 11% 18% 14% 2	2470
	11th to 20th	Night	50% 8% 9% 18% 13% 3	2404
	21st to end	Night	50% 9% 12% 15% 11% 3	1892
March	1st to 10th	Night	55% 10% 8% 18% 9% 1	3581
	11th to 20th	Night	39% 6% 10% 24% 22% 1	3490
	21st to end	Night	58% 10% 10% 14% 7% 1	3737
April	1st to 10th	Night	50% 8% 13% 18% 9% 1	1900
	11th to 20th	Night	43% 9% 14% 19% 12% 4	1879
	21st to end	Night	39% 11% 15% 22% 13% 1	1837
May	1st to 10th	Night	36% 7% 9% 26% 17% 5%	2732
	11th to 20th	Night	20% 5% 8% 27% 37% 3	2516
	21st to end	Night	22% 9% 17% 40% 12% 1	2762
June	1st to 10th	Night	36% 7% 14% 26% 16% 2	1520
	11th to 20th	Night	20% 7% 11% 32% 22% 6%	1520
	21st to end	Night	16% 3 7% 31% 33% 10%	1520
July	1st to 10th	Night	6% 2 5% 13% 17% 57%	2500
	11th to 20th	Night	12% 2 2 13% 23% 47%	2492
	21st to end	Night	9% 3 2 15% 38% 33%	2815
August	1st to 10th	Night	14% 3 4 17% 32% 31%	2839
	11th to 20th	Night	10% 3 3 29% 36% 20%	2857
	21st to end	Night	14% 2 6% 30% 29% 20%	3498
September	1st to 10th	Night	7% 4 3 19% 36% 31%	1900
	11th to 20th	Night	19% 6% 8% 22% 30% 16%	1900
	21st to end	Night	20% 5% 7% 25% 24% 19%	2164
October	1st to 10th	Night	22% 7% 9% 19% 29% 14%	2280
	11th to 20th	Night	30% 6% 9% 21% 24% 10%	2280
	21st to end	Night	35% 8% 11% 18% 17% 11%	2508
November	1st to 10th	Night	47% 8% 9% 15% 15% 6%	2404
	11th to 20th	Night	51% 9% 10% 13% 13% 4	2624
	21st to end	Night	47% 7% 9% 14% 15% 8%	2660
December	1st to 10th	Night	46% 7% 9% 19% 17% 3	2660
	11th to 20th	Night	59% 7% 6% 16% 11% 1	3276
	21st to end	Night	57% 8% 10% 13% 11% 2	4862

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	34% 22% 23% 14% 6%	180
	11th to 20th	Day	34% 18% 23% 17% 7% 2	228
	21st to end	Day	28% 18% 21% 22% 11% 1	407
February	1st to 10th	Day	26% 20% 29% 20% 5%	370
	11th to 20th	Day	31% 22% 22% 17% 8%	365
	21st to end	Day	28% 20% 26% 18% 7%	377
March	1st to 10th	Day	32% 21% 26% 17% 4	460
	11th to 20th	Day	27% 17% 26% 18% 11% 1	460
	21st to end	Day	31% 24% 25% 15% 4 1	506
April	1st to 10th	Day	27% 25% 22% 18% 7% 2	460
	11th to 20th	Day	29% 19% 28% 15% 6% 2	452
	21st to end	Day	21% 24% 28% 17% 8% 2	460
May	1st to 10th	Day	22% 18% 30% 20% 8% 2	463
	11th to 20th	Day	25% 17% 24% 20% 10% 3	488
	21st to end	Day	21% 15% 24% 23% 13% 4	529
June	1st to 10th	Day	18% 17% 27% 21% 14% 3	490
	11th to 20th	Day	16% 21% 31% 19% 12% 1	490
	21st to end	Day	6% 14% 31% 28% 17% 5%	490
July	1st to 10th	Day	6% 13% 35% 28% 14% 5%	486
	11th to 20th	Day	3 12% 34% 29% 17% 6%	484
	21st to end	Day	3 7% 34% 29% 20% 7%	531
August	1st to 10th	Day	2 10% 32% 28% 20% 8%	487
	11th to 20th	Day	5% 11% 28% 27% 20% 9%	477
	21st to end	Day	6% 10% 28% 30% 21% 6%	539
September	1st to 10th	Day	2 12% 29% 31% 20% 5%	490
	11th to 20th	Day	12% 12% 27% 29% 18% 3	490
	21st to end	Day	10% 15% 27% 30% 15% 2	490
October	1st to 10th	Day	15% 14% 27% 25% 16% 2	490
	11th to 20th	Day	18% 13% 23% 26% 18% 2	490
	21st to end	Day	23% 15% 27% 18% 14% 2	539
November	1st to 10th	Day	26% 12% 20% 27% 14%	275
	11th to 20th	Day	22% 9% 31% 22% 13% 3	196
	21st to end	Day	23% 19% 21% 23% 13% 1	180
December	1st to 10th	Day	29% 10% 28% 22% 7% 4	180
	11th to 20th	Day	32% 17% 22% 16% 13% 1	180
	21st to end	Day	26% 22% 22% 23% 6% 2	198
January	1st to 10th	Night	27% 15% 21% 22% 12% 3	760
	11th to 20th	Night	25% 14% 19% 24% 15% 3	760
	21st to end	Night	24% 11% 17% 27% 17% 4	836
February	1st to 10th	Night	22% 11% 23% 30% 12% 2	760
	11th to 20th	Night	21% 16% 20% 27% 16% 1	744
	21st to end	Night	20% 16% 22% 30% 11% 1	628
March	1st to 10th	Night	24% 17% 21% 25% 11% 3	760
	11th to 20th	Night	20% 14% 16% 29% 18% 2	760
	21st to end	Night	24% 17% 22% 25% 11% 1	836
April	1st to 10th	Night	25% 14% 20% 25% 14% 2	760
	11th to 20th	Night	18% 17% 23% 24% 15% 3	751
	21st to end	Night	18% 14% 20% 29% 17% 2	697
May	1st to 10th	Night	14% 10% 24% 30% 20% 2	494
	11th to 20th	Night	13% 9% 20% 34% 22% 3	374
	21st to end	Night	15% 9% 18% 32% 23% 2	411
June	1st to 10th	Night	17% 6% 18% 33% 23% 3	380
	11th to 20th	Night	7% 6% 23% 39% 23% 2	380
	21st to end	Night	7% 3 14% 44% 31% 2	380
July	1st to 10th	Night	4 2 12% 47% 34% 2	370
	11th to 20th	Night	2 1 17% 49% 30% 1	368
	21st to end	Night	1 1 11% 41% 40% 5%	499
August	1st to 10th	Night	3 1 9% 41% 39% 8%	567
	11th to 20th	Night	3 2 10% 34% 43% 9%	569
	21st to end	Night	4 3 18% 40% 30% 4	836
September	1st to 10th	Night	3 4 17% 39% 32% 5%	760
	11th to 20th	Night	7% 5% 16% 33% 33% 7%	760
	21st to end	Night	11% 6% 13% 34% 30% 6%	760
October	1st to 10th	Night	8% 8% 18% 34% 28% 4	760
	11th to 20th	Night	15% 8% 12% 33% 27% 5%	760
	21st to end	Night	18% 9% 18% 29% 19% 6%	836
November	1st to 10th	Night	23% 9% 20% 27% 16% 4	742
	11th to 20th	Night	24% 10% 18% 30% 15% 2	760
	21st to end	Night	21% 13% 19% 27% 18% 3	760
December	1st to 10th	Night	24% 11% 17% 30% 15% 3	760
	11th to 20th	Night	27% 12% 20% 27% 13% 2	760
	21st to end	Night	32% 15% 19% 25% 8% 1	836

Page generated at 2024-10-29 08:20:51. Version ac07

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