Otter Lake Scout Camp
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Otter Lake Scout Camp clear sky chart from 2005-11-06 to 2025-02-06.

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	16% 10% 3 8% 5% 4 4 4 5% 7% 33%	108614
	Night	17% 11% 4 9% 5% 4 4 3 5% 6% 31%	109628
Transparency	Day	50% 6% 11% 22% 10% 1	112166
	Night	52% 6% 11% 20% 11% 1	114240
Seeing	Day	24% 15% 31% 20% 8% 3	14717
	Night	23% 13% 30% 24% 9% 1	24026

By Month

Percentage Cloud Cover NE (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% 14% 5% 10% 6% 4 5% 3 5% 6% 28%	3597
	11th to 20th	Day	11% 18% 9% 13% 7% 5% 5% 3 4 5% 20%	3570
	21st to end	Day	13% 18% 7% 14% 6% 5% 4 4 4 4 20%	4309
February	1st to 10th	Day	15% 16% 4 11% 6% 5% 5% 5% 5% 5% 23%	1755
	11th to 20th	Day	12% 16% 4 12% 7% 5% 5% 3 3 5% 27%	1663
	21st to end	Day	19% 15% 4 8% 7% 5% 5% 3 4 5% 24%	1555
March	1st to 10th	Day	21% 13% 4 9% 6% 4 3 2 4 5% 29%	3202
	11th to 20th	Day	11% 17% 5% 9% 5% 5% 4 3 5% 5% 31%	3480
	21st to end	Day	13% 11% 3 8% 5% 3 3 3 4 6% 42%	3969
April	1st to 10th	Day	21% 14% 3 7% 5% 3 4 3 4 5% 32%	2280
	11th to 20th	Day	22% 8% 3 7% 4 3 4 3 4 5% 37%	2254
	21st to end	Day	22% 11% 3 8% 5% 4 4 3 4 5% 32%	2380
May	1st to 10th	Day	21% 8% 3 8% 5% 5% 5% 3 5% 6% 32%	4416
	11th to 20th	Day	17% 8% 3 9% 5% 4 5% 3 5% 8% 32%	4398
	21st to end	Day	14% 5% 2 6% 4 4 5% 4 7% 8% 41%	4837
June	1st to 10th	Day	19% 8% 3 7% 5% 4 5% 5% 6% 7% 31%	2660
	11th to 20th	Day	16% 5% 2 6% 5% 4 5% 4 6% 9% 37%	2660
	21st to end	Day	17% 8% 2 7% 5% 4 4 5% 6% 8% 33%	2660
July	1st to 10th	Day	11% 6% 3 7% 5% 5% 6% 5% 8% 9% 37%	4440
	11th to 20th	Day	12% 6% 2 6% 3 4 4 5% 7% 9% 41%	4440
	21st to end	Day	10% 6% 2 6% 5% 5% 5% 5% 8% 9% 40%	4814
August	1st to 10th	Day	17% 8% 3 7% 4 4 5% 3 6% 8% 36%	4210
	11th to 20th	Day	16% 7% 2 6% 4 4 5% 5% 6% 9% 36%	4021
	21st to end	Day	15% 6% 2 6% 4 4 4 4 7% 9% 39%	4180
September	1st to 10th	Day	13% 6% 3 6% 4 4 4 4 6% 7% 43%	2280
	11th to 20th	Day	12% 5% 2 5% 4 4 4 3 4 8% 49%	2280
	21st to end	Day	18% 6% 3 6% 4 3 4 4 5% 7% 40%	2012
October	1st to 10th	Day	20% 9% 2 7% 4 4 4 4 5% 5% 37%	1900
	11th to 20th	Day	21% 9% 3 7% 6% 4 3 3 6% 7% 31%	1900
	21st to end	Day	25% 11% 3 7% 6% 4 5% 3 4 6% 26%	1990
November	1st to 10th	Day	16% 8% 3 8% 6% 4 5% 5% 5% 7% 33%	1756
	11th to 20th	Day	17% 12% 4 9% 6% 5% 4 3 5% 6% 32%	1600
	21st to end	Day	21% 14% 5% 7% 6% 4 5% 4 6% 5% 24%	1600
December	1st to 10th	Day	22% 15% 5% 11% 6% 5% 4 3 5% 6% 19%	2600
	11th to 20th	Day	18% 20% 5% 10% 5% 5% 4 3 4 4 23%	2986
	21st to end	Day	22% 16% 4 12% 6% 4 3 3 3 4 24%	3960
January	1st to 10th	Night	15% 15% 6% 12% 6% 6% 4 3 4 5% 23%	6349
	11th to 20th	Night	11% 16% 6% 16% 8% 6% 5% 4 4 5% 18%	6315
	21st to end	Night	16% 15% 7% 14% 6% 5% 4 3 4 4 21%	6646
February	1st to 10th	Night	16% 14% 4 10% 7% 5% 5% 4 5% 6% 23%	2536
	11th to 20th	Night	13% 13% 5% 11% 6% 5% 4 3 4 5% 29%	2403
	21st to end	Night	16% 13% 4 9% 6% 5% 4 3 5% 6% 29%	1899
March	1st to 10th	Night	19% 12% 4 8% 5% 5% 4 3 4 5% 32%	3634
	11th to 20th	Night	18% 16% 5% 9% 5% 4 4 3 4 6% 27%	3479
	21st to end	Night	16% 10% 3 7% 5% 3 3 3 4 5% 41%	3663
April	1st to 10th	Night	21% 10% 4 7% 4 3 4 4 4 5% 34%	1900
	11th to 20th	Night	20% 9% 3 6% 5% 4 3 3 5% 5% 38%	1875
	21st to end	Night	21% 10% 3 6% 4 5% 4 3 5% 6% 32%	1815
May	1st to 10th	Night	22% 10% 3 6% 4 4 5% 4 5% 6% 31%	2524
	11th to 20th	Night	19% 9% 3 6% 4 4 4 3 5% 7% 38%	2495
	21st to end	Night	14% 6% 2 5% 4 4 5% 4 6% 8% 42%	2738
June	1st to 10th	Night	15% 7% 3 7% 6% 5% 5% 5% 6% 7% 34%	1520
	11th to 20th	Night	14% 5% 2 5% 5% 4 4 4 6% 8% 43%	1520
	21st to end	Night	17% 7% 2 7% 4 4 6% 4 5% 8% 37%	1520
July	1st to 10th	Night	11% 6% 3 7% 5% 5% 6% 4 7% 8% 39%	2520
	11th to 20th	Night	14% 6% 2 5% 4 4 3 4 6% 8% 44%	2520
	21st to end	Night	10% 6% 2 5% 4 4 5% 4 6% 8% 46%	2739
August	1st to 10th	Night	11% 8% 3 6% 4 4 4 4 6% 8% 43%	2716
	11th to 20th	Night	12% 8% 3 7% 4 4 3 3 5% 7% 44%	2785
	21st to end	Night	10% 5% 2 6% 5% 5% 5% 5% 8% 9% 41%	3466
September	1st to 10th	Night	11% 6% 2 7% 4 3 4 3 5% 7% 47%	1900
	11th to 20th	Night	13% 5% 2 5% 3 3 4 3 6% 6% 52%	1900
	21st to end	Night	18% 6% 2 5% 5% 4 4 3 5% 6% 42%	2163
October	1st to 10th	Night	16% 8% 3 7% 5% 4 4 4 5% 6% 38%	2280
	11th to 20th	Night	20% 9% 3 7% 5% 5% 4 4 5% 6% 32%	2280
	21st to end	Night	22% 10% 3 8% 5% 5% 5% 4 4 6% 29%	2607
November	1st to 10th	Night	18% 10% 3 6% 5% 3 4 4 6% 6% 36%	2537
	11th to 20th	Night	18% 11% 3 7% 4 4 5% 4 5% 6% 33%	2800
	21st to end	Night	20% 12% 4 9% 5% 5% 5% 4 4 7% 25%	2800
December	1st to 10th	Night	19% 15% 4 11% 7% 5% 5% 4 5% 6% 18%	4580
	11th to 20th	Night	23% 16% 4 8% 5% 4 3 3 4 5% 25%	5208
	21st to end	Night	26% 16% 4 10% 5% 4 3 2 5% 4 21%	6996

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	56% 7% 9% 19% 7% 1	3598
	11th to 20th	Day	68% 5% 10% 11% 6% 1	3600
	21st to end	Day	68% 5% 7% 9% 10% 1	4309
February	1st to 10th	Day	62% 5% 9% 18% 6% 1	1755
	11th to 20th	Day	60% 5% 9% 15% 10% 1	1672
	21st to end	Day	63% 5% 9% 12% 10% 1	1555
March	1st to 10th	Day	58% 4 9% 18% 9% 1	3205
	11th to 20th	Day	55% 6% 12% 15% 11% 2	3480
	21st to end	Day	42% 6% 7% 25% 16% 4	3969
April	1st to 10th	Day	55% 4 7% 18% 13% 3	2280
	11th to 20th	Day	49% 5% 6% 22% 15% 2	2254
	21st to end	Day	55% 4 8% 17% 13% 4	2380
May	1st to 10th	Day	51% 7% 9% 22% 10% 2	4430
	11th to 20th	Day	48% 7% 12% 22% 9% 1	4402
	21st to end	Day	39% 6% 13% 26% 14% 2	4837
June	1st to 10th	Day	49% 7% 11% 20% 12% 1	2660
	11th to 20th	Day	41% 6% 11% 26% 13% 2	2660
	21st to end	Day	46% 7% 14% 21% 11% 1	2660
July	1st to 10th	Day	40% 6% 13% 28% 12% 1	4370
	11th to 20th	Day	36% 7% 16% 32% 10%	4365
	21st to end	Day	38% 7% 14% 30% 10%	4661
August	1st to 10th	Day	45% 6% 14% 24% 10% 1	4196
	11th to 20th	Day	43% 6% 13% 27% 10% 1	4060
	21st to end	Day	40% 5% 14% 29% 11%	4180
September	1st to 10th	Day	38% 5% 15% 28% 13% 1	2280
	11th to 20th	Day	35% 5% 12% 31% 16% 1	2280
	21st to end	Day	43% 6% 13% 28% 10%	2012
October	1st to 10th	Day	42% 5% 13% 30% 9%	3160
	11th to 20th	Day	45% 5% 14% 28% 8%	3140
	21st to end	Day	50% 5% 14% 24% 8%	3254
November	1st to 10th	Day	48% 7% 13% 23% 8% 1	1756
	11th to 20th	Day	54% 5% 9% 20% 11% 1	1600
	21st to end	Day	59% 8% 12% 12% 8%	1600
December	1st to 10th	Day	66% 4 15% 10% 4	2600
	11th to 20th	Day	66% 5% 9% 13% 7%	2986
	21st to end	Day	64% 5% 8% 17% 6%	3960
January	1st to 10th	Night	62% 6% 11% 14% 6%	6349
	11th to 20th	Night	67% 6% 10% 11% 6%	6360
	21st to end	Night	66% 6% 8% 9% 11% 1	6646
February	1st to 10th	Night	61% 5% 11% 16% 6%	2536
	11th to 20th	Night	56% 5% 9% 20% 10% 1	2405
	21st to end	Night	57% 5% 10% 18% 10% 1	1899
March	1st to 10th	Night	53% 6% 8% 22% 10% 1	3644
	11th to 20th	Night	57% 6% 12% 15% 9% 1	3480
	21st to end	Night	43% 6% 5% 24% 19% 3	3663
April	1st to 10th	Night	52% 4 7% 20% 15% 2	1900
	11th to 20th	Night	49% 3 9% 19% 18% 2	1875
	21st to end	Night	53% 4 8% 16% 16% 3	1815
May	1st to 10th	Night	53% 5% 10% 18% 11% 3	2530
	11th to 20th	Night	47% 7% 12% 23% 10% 2	2496
	21st to end	Night	38% 6% 13% 22% 19% 2	2739
June	1st to 10th	Night	47% 6% 13% 21% 12% 1	1520
	11th to 20th	Night	37% 6% 13% 22% 19% 2	1520
	21st to end	Night	45% 7% 13% 21% 13% 1	1520
July	1st to 10th	Night	41% 7% 11% 23% 17% 1	2480
	11th to 20th	Night	36% 6% 12% 35% 11%	2472
	21st to end	Night	35% 7% 15% 29% 12% 2	2651
August	1st to 10th	Night	39% 6% 14% 26% 14% 1	2706
	11th to 20th	Night	39% 6% 12% 33% 10% 1	2812
	21st to end	Night	37% 7% 14% 30% 12% 1	3466
September	1st to 10th	Night	37% 5% 12% 31% 14% 1	1900
	11th to 20th	Night	31% 6% 14% 34% 13% 1	1900
	21st to end	Night	41% 5% 11% 30% 12% 1	2163
October	1st to 10th	Night	39% 5% 11% 28% 17%	3800
	11th to 20th	Night	44% 4 13% 28% 10%	3779
	21st to end	Night	49% 5% 13% 24% 8%	4293
November	1st to 10th	Night	47% 6% 12% 23% 11% 1	2537
	11th to 20th	Night	50% 6% 12% 19% 11% 2	2800
	21st to end	Night	59% 6% 12% 16% 6%	2800
December	1st to 10th	Night	65% 6% 12% 14% 3	4580
	11th to 20th	Night	61% 5% 9% 15% 10% 1	5208
	21st to end	Night	66% 5% 7% 11% 10%	6996

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	27% 18% 38% 14% 3 1	200
	11th to 20th	Day	31% 19% 32% 16% 3 1	200
	21st to end	Day	28% 24% 29% 16% 4	297
February	1st to 10th	Day	34% 26% 29% 9% 1	285
	11th to 20th	Day	31% 27% 34% 8%	270
	21st to end	Day	34% 19% 33% 13% 2	367
March	1st to 10th	Day	26% 20% 34% 15% 5%	460
	11th to 20th	Day	30% 19% 32% 15% 3 1	460
	21st to end	Day	31% 21% 29% 12% 6% 1	506
April	1st to 10th	Day	30% 20% 32% 13% 5%	460
	11th to 20th	Day	33% 21% 24% 12% 7% 3	452
	21st to end	Day	30% 21% 30% 12% 5% 2	460
May	1st to 10th	Day	26% 13% 30% 23% 6% 2	463
	11th to 20th	Day	20% 12% 37% 21% 8% 2	487
	21st to end	Day	17% 16% 30% 25% 9% 2	529
June	1st to 10th	Day	26% 10% 33% 22% 7% 2	490
	11th to 20th	Day	18% 13% 34% 20% 12% 3	490
	21st to end	Day	23% 13% 31% 21% 10% 2	490
July	1st to 10th	Day	14% 9% 30% 28% 14% 4	485
	11th to 20th	Day	15% 11% 29% 26% 14% 4	484
	21st to end	Day	14% 7% 36% 28% 9% 4	532
August	1st to 10th	Day	17% 5% 32% 28% 15% 4	486
	11th to 20th	Day	14% 6% 28% 30% 15% 6%	479
	21st to end	Day	15% 10% 31% 26% 11% 6%	539
September	1st to 10th	Day	15% 9% 33% 26% 11% 7%	490
	11th to 20th	Day	12% 8% 24% 27% 17% 12%	490
	21st to end	Day	19% 11% 29% 26% 13% 3	490
October	1st to 10th	Day	29% 13% 26% 17% 10% 4	490
	11th to 20th	Day	27% 19% 30% 16% 6% 2	490
	21st to end	Day	31% 18% 26% 20% 4	486
November	1st to 10th	Day	28% 17% 29% 18% 7% 1	390
	11th to 20th	Day	28% 12% 42% 10% 7% 2	200
	21st to end	Day	29% 22% 32% 13% 4 1	200
December	1st to 10th	Day	34% 19% 30% 14% 4	200
	11th to 20th	Day	32% 24% 33% 9% 3	200
	21st to end	Day	35% 16% 33% 12% 4	220
January	1st to 10th	Night	30% 16% 31% 18% 4	800
	11th to 20th	Night	30% 19% 28% 18% 5%	800
	21st to end	Night	22% 16% 36% 22% 4	880
February	1st to 10th	Night	27% 18% 34% 19% 2	781
	11th to 20th	Night	23% 18% 39% 16% 3	743
	21st to end	Night	25% 19% 35% 18% 3	628
March	1st to 10th	Night	24% 16% 36% 20% 4	760
	11th to 20th	Night	28% 18% 28% 21% 4 1	760
	21st to end	Night	24% 15% 33% 20% 7%	836
April	1st to 10th	Night	26% 16% 33% 21% 3	760
	11th to 20th	Night	23% 20% 31% 17% 8%	751
	21st to end	Night	27% 12% 29% 22% 9%	675
May	1st to 10th	Night	26% 8% 26% 28% 11% 1	390
	11th to 20th	Night	15% 9% 36% 33% 7%	374
	21st to end	Night	13% 9% 36% 30% 11% 1	411
June	1st to 10th	Night	16% 8% 33% 32% 10% 1	380
	11th to 20th	Night	17% 8% 29% 33% 13% 1	380
	21st to end	Night	20% 5% 25% 36% 14%	380
July	1st to 10th	Night	10% 5% 29% 38% 17%	370
	11th to 20th	Night	12% 3 28% 38% 17% 1	368
	21st to end	Night	12% 4 26% 41% 15% 1	416
August	1st to 10th	Night	14% 3 24% 36% 22% 1	497
	11th to 20th	Night	15% 3 23% 33% 23% 3	564
	21st to end	Night	12% 6% 29% 35% 16% 2	826
September	1st to 10th	Night	15% 6% 29% 32% 16% 3	760
	11th to 20th	Night	15% 6% 20% 27% 25% 6%	760
	21st to end	Night	20% 9% 23% 28% 17% 3	760
October	1st to 10th	Night	21% 11% 28% 21% 17% 2	760
	11th to 20th	Night	26% 13% 28% 23% 8% 1	760
	21st to end	Night	27% 15% 28% 24% 6%	836
November	1st to 10th	Night	26% 14% 29% 22% 8%	780
	11th to 20th	Night	25% 16% 32% 19% 8% 1	800
	21st to end	Night	31% 18% 28% 17% 7%	800
December	1st to 10th	Night	31% 17% 29% 20% 4	800
	11th to 20th	Night	29% 19% 33% 15% 3 1	800
	21st to end	Night	35% 15% 30% 17% 3	880

Page generated at 2025-02-03 03:05:51. Version ac07

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