Pickerel Lake
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Pickerel Lake clear sky chart from 2005-11-06 to 2025-09-19.

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	11% 8% 3 8% 5% 4 5% 4 6% 7% 40%	135125
	Night	9% 8% 3 8% 5% 5% 5% 4 6% 7% 40%	131220
Transparency	Day	42% 5% 13% 26% 12% 1	129784
	Night	43% 4 13% 25% 13% 2	127568
Seeing	Day	15% 11% 32% 28% 12% 2	17300
	Night	13% 11% 36% 31% 9% 1	27110

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	6% 13% 4 12% 11% 9% 11% 4 6% 7% 17%	3270
	11th to 20th	Day	4 8% 3 10% 7% 6% 10% 11% 12% 10% 20%	3640
	21st to end	Day	3 7% 4 19% 9% 6% 6% 4 6% 6% 30%	4224
February	1st to 10th	Day	8% 12% 4 13% 6% 7% 6% 5% 6% 8% 26%	1800
	11th to 20th	Day	7% 8% 5% 11% 7% 7% 7% 6% 6% 7% 29%	1759
	21st to end	Day	7% 12% 3 12% 6% 8% 6% 4 6% 7% 30%	1650
March	1st to 10th	Day	9% 9% 3 7% 5% 4 4 3 5% 7% 44%	4670
	11th to 20th	Day	9% 10% 3 8% 5% 4 4 4 6% 9% 38%	4980
	21st to end	Day	18% 14% 6% 12% 7% 4 4 3 5% 7% 20%	5464
April	1st to 10th	Day	15% 10% 4 5% 5% 3 4 4 4 6% 39%	2330
	11th to 20th	Day	16% 13% 4 8% 4 4 4 3 5% 6% 32%	2569
	21st to end	Day	19% 11% 4 7% 5% 4 4 3 5% 6% 34%	2600
May	1st to 10th	Day	10% 6% 2 5% 3 3 4 3 5% 7% 51%	5900
	11th to 20th	Day	19% 9% 2 5% 3 3 3 2 5% 6% 43%	6035
	21st to end	Day	15% 6% 2 6% 5% 5% 5% 5% 6% 8% 36%	7203
June	1st to 10th	Day	11% 6% 2 6% 4 5% 4 4 7% 9% 44%	3000
	11th to 20th	Day	14% 7% 2 6% 5% 4 4 5% 5% 9% 40%	3000
	21st to end	Day	10% 5% 2 6% 4 4 4 3 7% 8% 47%	3000
July	1st to 10th	Day	8% 4 2 5% 4 4 5% 4 7% 10% 47%	6799
	11th to 20th	Day	6% 4 2 5% 4 4 4 3 5% 7% 55%	6582
	21st to end	Day	7% 4 2 7% 5% 5% 5% 5% 7% 10% 44%	6715
August	1st to 10th	Day	13% 6% 2 5% 4 4 4 4 6% 8% 43%	5801
	11th to 20th	Day	11% 6% 2 7% 4 5% 4 4 6% 9% 42%	5821
	21st to end	Day	8% 4 2 5% 4 3 4 3 6% 7% 54%	6490
September	1st to 10th	Day	10% 4 2 5% 3 3 4 3 5% 7% 53%	2373
	11th to 20th	Day	9% 5% 2 5% 3 3 4 3 6% 8% 49%	2178
	21st to end	Day	13% 7% 2 5% 3 3 3 3 4 6% 51%	2090
October	1st to 10th	Day	12% 5% 2 5% 3 3 3 2 4 6% 56%	3266
	11th to 20th	Day	11% 7% 3 6% 4 4 3 3 3 5% 50%	3140
	21st to end	Day	12% 10% 3 7% 4 3 4 3 6% 6% 41%	3163
November	1st to 10th	Day	12% 10% 5% 8% 5% 3 3 3 5% 7% 39%	1758
	11th to 20th	Day	9% 11% 4 12% 7% 5% 4 4 5% 6% 34%	1600
	21st to end	Day	8% 11% 3 10% 7% 6% 4 3 5% 8% 34%	1600
December	1st to 10th	Day	5% 8% 4 14% 9% 8% 6% 5% 7% 8% 24%	2514
	11th to 20th	Day	7% 12% 5% 12% 7% 7% 7% 6% 7% 8% 22%	2643
	21st to end	Day	12% 13% 5% 12% 9% 5% 5% 3 4 5% 27%	3498
January	1st to 10th	Night	4 9% 4 13% 10% 9% 10% 6% 7% 9% 18%	6677
	11th to 20th	Night	3 7% 3 10% 8% 6% 10% 10% 11% 9% 23%	6340
	21st to end	Night	3 8% 5% 16% 6% 5% 5% 4 6% 7% 35%	6740
February	1st to 10th	Night	7% 10% 4 10% 7% 7% 7% 6% 6% 7% 29%	2600
	11th to 20th	Night	5% 9% 4 8% 6% 5% 6% 6% 7% 7% 36%	2533
	21st to end	Night	8% 10% 4 9% 7% 4 5% 5% 6% 7% 35%	1991
March	1st to 10th	Night	8% 7% 3 7% 6% 5% 5% 4 5% 8% 42%	5195
	11th to 20th	Night	9% 8% 3 8% 6% 4 5% 4 6% 8% 39%	4980
	21st to end	Night	17% 12% 4 7% 6% 4 5% 3 5% 6% 29%	5467
April	1st to 10th	Night	12% 11% 3 6% 4 4 5% 4 5% 8% 38%	2065
	11th to 20th	Night	16% 8% 3 7% 5% 4 4 3 5% 6% 38%	1779
	21st to end	Night	17% 11% 3 7% 4 3 5% 3 4 6% 36%	1800
May	1st to 10th	Night	13% 4 2 4 3 2 3 3 4 6% 56%	4080
	11th to 20th	Night	13% 9% 2 5% 4 3 4 3 5% 5% 46%	3876
	21st to end	Night	14% 8% 2 6% 4 4 5% 4 5% 7% 41%	3690
June	1st to 10th	Night	10% 5% 2 4 3 3 4 4 7% 9% 49%	1400
	11th to 20th	Night	9% 6% 2 6% 5% 4 4 4 6% 8% 47%	1400
	21st to end	Night	8% 3 2 4 3 3 3 4 5% 7% 59%	1400
July	1st to 10th	Night	8% 4 2 5% 4 3 4 4 6% 9% 52%	3180
	11th to 20th	Night	6% 3 1 4 3 3 3 3 5% 7% 62%	3381
	21st to end	Night	7% 5% 2 6% 4 5% 5% 4 7% 9% 47%	4143
August	1st to 10th	Night	12% 8% 2 6% 4 4 4 4 5% 7% 46%	4011
	11th to 20th	Night	10% 7% 2 6% 3 3 4 3 4 7% 49%	4028
	21st to end	Night	7% 4 1 5% 3 4 4 3 5% 7% 57%	4487
September	1st to 10th	Night	9% 3 1 3 3 3 3 3 4 6% 61%	2024
	11th to 20th	Night	8% 6% 2 5% 4 3 4 3 5% 6% 55%	2178
	21st to end	Night	11% 5% 2 4 3 3 3 3 4 5% 56%	2090
October	1st to 10th	Night	8% 4 1 3 2 3 3 3 4 5% 64%	3662
	11th to 20th	Night	9% 6% 2 5% 3 4 4 4 6% 7% 49%	3779
	21st to end	Night	12% 9% 3 6% 4 3 3 3 5% 6% 46%	4391
November	1st to 10th	Night	9% 9% 3 8% 5% 4 5% 4 5% 6% 42%	2538
	11th to 20th	Night	8% 9% 4 11% 6% 5% 4 4 5% 6% 38%	2800
	21st to end	Night	8% 9% 3 9% 7% 5% 4 3 6% 7% 38%	2800
December	1st to 10th	Night	4 8% 4 12% 7% 8% 7% 5% 6% 8% 32%	4671
	11th to 20th	Night	7% 11% 4 12% 8% 8% 6% 5% 6% 6% 26%	5564
	21st to end	Night	11% 13% 5% 13% 8% 6% 5% 4 5% 6% 24%	7480

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% 12% 8% 1	3271
	11th to 20th	Day	53% 5% 11% 20% 10%	3640
	21st to end	Day	54% 6% 15% 16% 9%	4224
February	1st to 10th	Day	55% 5% 12% 19% 9% 1	1800
	11th to 20th	Day	50% 5% 12% 22% 9% 2	1768
	21st to end	Day	52% 6% 14% 18% 9% 1	1650
March	1st to 10th	Day	39% 4 14% 31% 10% 2	4670
	11th to 20th	Day	42% 3 11% 30% 11% 1	4980
	21st to end	Day	64% 4 11% 16% 4 1	5464
April	1st to 10th	Day	45% 4 12% 24% 13% 1	2330
	11th to 20th	Day	53% 4 10% 21% 12% 1	2572
	21st to end	Day	51% 3 12% 24% 9% 1	2600
May	1st to 10th	Day	32% 4 9% 31% 22%	5900
	11th to 20th	Day	43% 4 9% 23% 14% 7%	6039
	21st to end	Day	43% 6% 12% 29% 11%	7204
June	1st to 10th	Day	35% 5% 17% 30% 11% 1	3000
	11th to 20th	Day	40% 5% 15% 26% 12% 2	3000
	21st to end	Day	33% 5% 18% 29% 14% 1	3000
July	1st to 10th	Day	31% 6% 20% 30% 13% 1	6726
	11th to 20th	Day	28% 4 13% 38% 15% 2	6501
	21st to end	Day	34% 7% 19% 27% 12% 1	6521
August	1st to 10th	Day	36% 5% 13% 30% 14% 3	4220
	11th to 20th	Day	41% 6% 14% 31% 7% 1	4210
	21st to end	Day	32% 5% 16% 31% 14% 2	4674
September	1st to 10th	Day	30% 5% 14% 36% 15% 1	2373
	11th to 20th	Day	33% 4 19% 33% 11% 1	2178
	21st to end	Day	35% 3 12% 31% 17% 2	2090
October	1st to 10th	Day	31% 2 9% 30% 25% 2	3266
	11th to 20th	Day	38% 4 8% 29% 20% 3	3140
	21st to end	Day	43% 4 14% 23% 15%	3163
November	1st to 10th	Day	45% 4 12% 23% 14% 3	1758
	11th to 20th	Day	51% 4 13% 19% 11% 1	1600
	21st to end	Day	49% 4 15% 22% 8% 2	1600
December	1st to 10th	Day	57% 6% 16% 16% 5% 1	2514
	11th to 20th	Day	60% 5% 15% 16% 4	2640
	21st to end	Day	60% 3 10% 17% 8%	3498
January	1st to 10th	Night	61% 5% 10% 17% 7%	6677
	11th to 20th	Night	51% 5% 14% 16% 12% 2	6340
	21st to end	Night	48% 5% 14% 21% 11%	6740
February	1st to 10th	Night	51% 5% 12% 18% 13% 1	2600
	11th to 20th	Night	44% 5% 12% 23% 13% 2	2534
	21st to end	Night	47% 6% 12% 20% 13% 3	1991
March	1st to 10th	Night	40% 3 12% 29% 13% 3	5195
	11th to 20th	Night	40% 4 14% 27% 14% 1	4980
	21st to end	Night	56% 4 12% 21% 7% 1	5467
April	1st to 10th	Night	43% 5% 11% 28% 12% 1	2065
	11th to 20th	Night	46% 4 7% 25% 14% 2	1779
	21st to end	Night	49% 4 11% 24% 11% 1	1800
May	1st to 10th	Night	30% 3 11% 32% 22% 3	4080
	11th to 20th	Night	39% 5% 8% 21% 21% 6%	3877
	21st to end	Night	42% 4 12% 31% 10%	3691
June	1st to 10th	Night	30% 4 18% 31% 14% 3	1400
	11th to 20th	Night	33% 5% 19% 25% 15% 3	1400
	21st to end	Night	25% 4 19% 31% 19% 2	1400
July	1st to 10th	Night	29% 6% 17% 32% 15% 1	3145
	11th to 20th	Night	23% 4 12% 44% 16% 2	3339
	21st to end	Night	32% 7% 18% 29% 12% 2	4024
August	1st to 10th	Night	32% 4 15% 29% 16% 4	2916
	11th to 20th	Night	35% 6% 16% 31% 11% 1	2915
	21st to end	Night	31% 6% 14% 29% 18% 2	3234
September	1st to 10th	Night	25% 3 14% 36% 20% 1	2024
	11th to 20th	Night	31% 4 15% 31% 17% 1	2178
	21st to end	Night	30% 4 12% 31% 20% 3	2090
October	1st to 10th	Night	24% 3 8% 30% 31% 3	3662
	11th to 20th	Night	34% 3 11% 28% 22% 2	3779
	21st to end	Night	40% 3 12% 28% 15% 1	4391
November	1st to 10th	Night	42% 4 12% 21% 18% 3	2538
	11th to 20th	Night	45% 5% 14% 19% 14% 2	2800
	21st to end	Night	44% 5% 15% 24% 10% 1	2800
December	1st to 10th	Night	50% 6% 18% 18% 8%	4671
	11th to 20th	Night	57% 4 15% 18% 5%	5566
	21st to end	Night	62% 4 9% 18% 7%	7480

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	14% 14% 33% 31% 6% 2	300
	11th to 20th	Day	11% 15% 40% 27% 6%	300
	21st to end	Day	13% 15% 41% 22% 9%	330
February	1st to 10th	Day	14% 16% 42% 25% 3	300
	11th to 20th	Day	13% 15% 45% 18% 8% 1	300
	21st to end	Day	13% 13% 50% 21% 3	249
March	1st to 10th	Day	16% 16% 38% 25% 4 1	300
	11th to 20th	Day	13% 14% 39% 25% 7% 2	300
	21st to end	Day	20% 13% 29% 25% 10% 2	330
April	1st to 10th	Day	24% 16% 31% 24% 6%	430
	11th to 20th	Day	26% 17% 30% 19% 8% 1	690
	21st to end	Day	22% 11% 34% 22% 10% 2	700
May	1st to 10th	Day	18% 10% 33% 27% 11% 1	703
	11th to 20th	Day	22% 11% 26% 28% 13% 2	725
	21st to end	Day	18% 8% 28% 31% 12% 2	789
June	1st to 10th	Day	9% 9% 27% 32% 19% 3	730
	11th to 20th	Day	17% 9% 37% 24% 10% 2	730
	21st to end	Day	14% 8% 31% 32% 13% 2	730
July	1st to 10th	Day	7% 5% 27% 35% 21% 5%	721
	11th to 20th	Day	6% 7% 31% 35% 17% 4	718
	21st to end	Day	5% 5% 29% 37% 20% 4	794
August	1st to 10th	Day	11% 5% 24% 37% 20% 3	726
	11th to 20th	Day	13% 5% 27% 32% 18% 4	715
	21st to end	Day	10% 6% 27% 34% 20% 3	803
September	1st to 10th	Day	11% 10% 30% 31% 16% 3	503
	11th to 20th	Day	11% 7% 37% 30% 12% 2	324
	21st to end	Day	19% 16% 27% 24% 11% 3	300
October	1st to 10th	Day	19% 11% 29% 26% 12% 2	300
	11th to 20th	Day	15% 18% 35% 26% 5% 1	300
	21st to end	Day	18% 21% 37% 16% 7% 1	330
November	1st to 10th	Day	20% 15% 33% 26% 5% 1	300
	11th to 20th	Day	18% 18% 38% 21% 4 1	300
	21st to end	Day	14% 21% 37% 23% 4 1	300
December	1st to 10th	Day	15% 13% 44% 20% 8% 1	300
	11th to 20th	Day	13% 18% 42% 25% 3	300
	21st to end	Day	22% 13% 38% 21% 5% 1	330
January	1st to 10th	Night	10% 14% 43% 26% 6% 1	1000
	11th to 20th	Night	11% 13% 43% 28% 4 1	1000
	21st to end	Night	11% 13% 45% 26% 5%	1100
February	1st to 10th	Night	12% 13% 42% 28% 5% 1	1000
	11th to 20th	Night	10% 13% 45% 25% 6% 1	979
	21st to end	Night	13% 11% 40% 25% 9% 2	671
March	1st to 10th	Night	12% 12% 41% 27% 7% 1	725
	11th to 20th	Night	15% 13% 39% 27% 6%	600
	21st to end	Night	15% 10% 33% 30% 11% 1	660
April	1st to 10th	Night	17% 11% 37% 29% 6%	600
	11th to 20th	Night	19% 14% 31% 26% 10% 1	593
	21st to end	Night	22% 10% 32% 26% 10% 1	600
May	1st to 10th	Night	15% 11% 32% 33% 9% 1	600
	11th to 20th	Night	16% 7% 32% 34% 11%	591
	21st to end	Night	14% 6% 32% 35% 12% 1	650
June	1st to 10th	Night	11% 8% 26% 38% 17% 1	600
	11th to 20th	Night	10% 8% 35% 40% 8%	600
	21st to end	Night	10% 6% 30% 43% 12% 1	600
July	1st to 10th	Night	7% 3 25% 43% 20% 2	585
	11th to 20th	Night	4 3 29% 47% 15% 1	582
	21st to end	Night	4 3 28% 48% 16% 1	657
August	1st to 10th	Night	9% 3 24% 48% 16% 2	597
	11th to 20th	Night	10% 4 24% 41% 19% 3	594
	21st to end	Night	7% 4 30% 40% 18% 1	660
September	1st to 10th	Night	9% 6% 31% 38% 15% 2	600
	11th to 20th	Night	9% 9% 32% 34% 13% 2	594
	21st to end	Night	13% 8% 35% 29% 13% 1	570
October	1st to 10th	Night	16% 13% 30% 32% 9% 1	674
	11th to 20th	Night	17% 16% 35% 24% 7%	760
	21st to end	Night	19% 14% 36% 25% 5%	993
November	1st to 10th	Night	13% 13% 39% 28% 7%	975
	11th to 20th	Night	13% 14% 40% 25% 7% 1	1000
	21st to end	Night	12% 15% 43% 26% 4	1000
December	1st to 10th	Night	11% 14% 44% 24% 7%	1000
	11th to 20th	Night	15% 14% 41% 26% 4 1	1000
	21st to end	Night	19% 12% 42% 21% 5% 1	1100

Page generated at 2025-09-16 00:49:13. Version ac07

Copyright © 2025 Attilla Danko.