Hugo Lake State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Hugo Lake State Park clear sky chart from 2005-11-06 to 2026-06-01.

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	14% 6% 2 5% 4 4 4 3 5% 7% 48%	132550
	Night	13% 5% 2 5% 3 3 3 3 4 6% 52%	130913
Transparency	Day	35% 5% 10% 24% 20% 6%	136189
	Night	32% 4 9% 23% 23% 9%	135338
Seeing	Day	15% 9% 23% 28% 19% 5%	17342
	Night	15% 8% 26% 33% 16% 1	27237

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% 7% 2 4 3 3 4 2 4 6% 50%	5289
	11th to 20th	Day	7% 5% 2 4 2 3 3 3 4 6% 62%	5310
	21st to end	Day	22% 7% 3 6% 3 2 3 2 3 4 44%	5812
February	1st to 10th	Day	23% 7% 2 6% 3 3 3 2 3 5% 43%	1890
	11th to 20th	Day	20% 7% 2 5% 4 3 3 3 4 5% 43%	2007
	21st to end	Day	24% 5% 2 5% 2 3 3 2 3 4 47%	1844
March	1st to 10th	Day	22% 6% 1 5% 3 3 3 3 4 6% 46%	5046
	11th to 20th	Day	12% 6% 2 5% 3 3 4 3 5% 6% 51%	5090
	21st to end	Day	17% 9% 2 6% 4 4 4 3 5% 6% 41%	5583
April	1st to 10th	Day	19% 6% 2 6% 3 4 3 3 4 6% 44%	2326
	11th to 20th	Day	20% 5% 2 5% 4 3 4 3 5% 7% 43%	2494
	21st to end	Day	20% 7% 3 5% 4 3 4 4 5% 6% 40%	2551
May	1st to 10th	Day	20% 7% 2 7% 4 4 4 3 5% 6% 38%	5992
	11th to 20th	Day	14% 6% 3 6% 4 4 5% 4 5% 7% 42%	5992
	21st to end	Day	18% 8% 3 7% 4 4 4 3 5% 7% 37%	6577
June	1st to 10th	Day	9% 4 2 6% 5% 5% 5% 4 7% 9% 44%	2601
	11th to 20th	Day	8% 6% 2 7% 5% 4 5% 4 7% 8% 44%	2600
	21st to end	Day	5% 4 2 4 4 4 4 4 7% 8% 54%	2600
July	1st to 10th	Day	7% 6% 2 7% 5% 6% 6% 5% 8% 10% 37%	5900
	11th to 20th	Day	5% 3 2 4 3 3 4 4 6% 9% 59%	5900
	21st to end	Day	6% 4 2 5% 4 5% 5% 4 7% 9% 47%	6422
August	1st to 10th	Day	3 2 1 3 3 3 4 3 6% 8% 63%	4234
	11th to 20th	Day	7% 4 1 4 3 3 4 4 7% 10% 53%	4171
	21st to end	Day	5% 3 1 5% 4 5% 6% 5% 7% 10% 48%	4312
September	1st to 10th	Day	11% 4 2 5% 4 4 4 4 5% 6% 51%	2268
	11th to 20th	Day	9% 5% 2 6% 4 4 5% 4 5% 8% 48%	2200
	21st to end	Day	8% 4 2 4 4 3 4 4 5% 7% 55%	2200
October	1st to 10th	Day	8% 4 2 4 3 4 3 3 4 5% 59%	2050
	11th to 20th	Day	14% 5% 2 4 3 2 2 2 3 4 60%	2000
	21st to end	Day	18% 6% 2 4 3 3 3 2 3 4 52%	2200
November	1st to 10th	Day	16% 5% 1 4 3 3 3 2 4 7% 51%	2058
	11th to 20th	Day	13% 4 2 4 3 3 3 2 4 6% 56%	2043
	21st to end	Day	20% 4 2 4 2 3 2 2 4 5% 52%	1890
December	1st to 10th	Day	20% 6% 2 4 2 2 2 2 4 5% 50%	3030
	11th to 20th	Day	24% 7% 2 4 3 2 2 2 4 6% 44%	3481
	21st to end	Day	25% 9% 2 4 2 3 3 2 4 5% 42%	4587
January	1st to 10th	Night	13% 6% 2 6% 3 3 3 3 4 6% 52%	7634
	11th to 20th	Night	7% 4 1 3 2 2 2 2 4 4 69%	7680
	21st to end	Night	25% 7% 2 5% 3 3 2 2 3 5% 42%	8402
February	1st to 10th	Night	20% 7% 2 5% 4 3 3 3 3 4 46%	2730
	11th to 20th	Night	19% 7% 3 5% 3 2 4 3 4 6% 45%	2517
	21st to end	Night	18% 5% 2 5% 2 3 3 3 3 4 51%	1961
March	1st to 10th	Night	21% 7% 2 6% 3 3 3 3 4 5% 44%	5029
	11th to 20th	Night	11% 5% 2 5% 3 3 3 2 4 6% 56%	5090
	21st to end	Night	17% 6% 2 5% 4 4 3 3 4 6% 47%	5588
April	1st to 10th	Night	15% 6% 1 5% 3 3 4 3 5% 6% 49%	2293
	11th to 20th	Night	16% 5% 1 4 4 3 3 3 5% 7% 47%	2075
	21st to end	Night	16% 6% 2 5% 3 3 3 3 5% 8% 46%	2063
May	1st to 10th	Night	21% 7% 2 5% 4 3 4 3 5% 7% 39%	4143
	11th to 20th	Night	12% 4 2 5% 4 4 5% 4 6% 8% 46%	4143
	21st to end	Night	14% 7% 1 6% 4 4 4 3 6% 8% 43%	4542
June	1st to 10th	Night	6% 4 2 4 4 3 4 4 6% 10% 55%	1800
	11th to 20th	Night	6% 4 2 5% 2 3 4 3 6% 8% 58%	1800
	21st to end	Night	4 2 1 3 2 2 3 3 6% 9% 63%	1800
July	1st to 10th	Night	6% 4 2 5% 5% 4 5% 5% 7% 11% 45%	4078
	11th to 20th	Night	5% 2 1 3 3 3 3 3 5% 7% 65%	4077
	21st to end	Night	3 3 1 5% 4 4 5% 4 6% 9% 56%	4449
August	1st to 10th	Night	2 2 1 2 2 3 3 3 4 8% 69%	2926
	11th to 20th	Night	4 2 1 4 3 3 3 3 6% 10% 62%	2888
	21st to end	Night	3 3 1 5% 4 4 5% 4 6% 8% 57%	3585
September	1st to 10th	Night	7% 4 2 5% 3 4 4 3 5% 7% 57%	2128
	11th to 20th	Night	10% 4 2 5% 4 4 4 4 6% 6% 52%	2200
	21st to end	Night	8% 3 1 4 3 4 3 3 4 7% 60%	2200
October	1st to 10th	Night	8% 3 1 2 3 3 3 3 5% 6% 63%	2330
	11th to 20th	Night	12% 4 1 3 2 2 3 2 4 5% 62%	2400
	21st to end	Night	17% 5% 2 5% 2 2 2 2 3 4 56%	2640
November	1st to 10th	Night	14% 4 1 5% 2 2 2 2 3 5% 59%	2460
	11th to 20th	Night	11% 6% 1 4 2 2 3 3 4 6% 59%	2573
	21st to end	Night	18% 6% 2 3 3 3 3 3 4 5% 51%	2730
December	1st to 10th	Night	14% 7% 2 5% 3 3 3 3 4 5% 52%	4380
	11th to 20th	Night	20% 6% 2 5% 4 3 2 2 3 4 47%	4946
	21st to end	Night	20% 9% 3 5% 2 2 2 2 3 5% 46%	6633

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	36% 3 9% 28% 22% 2	5290
	11th to 20th	Day	24% 3 8% 24% 37% 4	5310
	21st to end	Day	46% 2 4 18% 21% 10%	5812
February	1st to 10th	Day	46% 3 7% 18% 21% 5%	1890
	11th to 20th	Day	45% 3 6% 21% 20% 5%	2017
	21st to end	Day	43% 2 6% 15% 25% 9%	1844
March	1st to 10th	Day	41% 3 5% 16% 19% 16%	5046
	11th to 20th	Day	34% 4 7% 17% 19% 19%	5090
	21st to end	Day	44% 4 9% 23% 17% 2	5585
April	1st to 10th	Day	42% 3 9% 20% 19% 7%	2326
	11th to 20th	Day	41% 5% 9% 19% 21% 6%	2494
	21st to end	Day	45% 6% 8% 20% 18% 4	2551
May	1st to 10th	Day	47% 5% 9% 24% 13% 2	6030
	11th to 20th	Day	42% 5% 12% 21% 18% 3	5996
	21st to end	Day	46% 6% 12% 19% 15% 3	6590
June	1st to 10th	Day	35% 7% 13% 26% 16% 2	2601
	11th to 20th	Day	35% 6% 13% 26% 18% 2	2600
	21st to end	Day	26% 7% 14% 30% 21% 2	2600
July	1st to 10th	Day	37% 9% 17% 26% 9% 1	5836
	11th to 20th	Day	21% 5% 13% 38% 21% 1	5831
	21st to end	Day	29% 8% 14% 34% 15% 1	6240
August	1st to 10th	Day	18% 5% 13% 29% 29% 7%	4220
	11th to 20th	Day	26% 5% 18% 36% 13% 2	4210
	21st to end	Day	28% 8% 17% 31% 14% 2	4311
September	1st to 10th	Day	33% 6% 8% 23% 20% 10%	2268
	11th to 20th	Day	33% 7% 10% 23% 20% 7%	2200
	21st to end	Day	28% 5% 9% 21% 25% 11%	2200
October	1st to 10th	Day	17% 3 6% 12% 34% 29%	3336
	11th to 20th	Day	21% 3 4 18% 34% 21%	3240
	21st to end	Day	31% 4 5% 28% 24% 8%	3538
November	1st to 10th	Day	34% 4 8% 23% 24% 8%	2058
	11th to 20th	Day	30% 3 8% 21% 27% 10%	2043
	21st to end	Day	36% 3 6% 21% 27% 7%	1890
December	1st to 10th	Day	38% 3 6% 33% 18% 3	3030
	11th to 20th	Day	44% 2 5% 20% 24% 5%	3479
	21st to end	Day	45% 2 4 22% 21% 4	4587
January	1st to 10th	Night	35% 3 7% 28% 24% 3	7635
	11th to 20th	Night	20% 3 6% 20% 38% 13%	7680
	21st to end	Night	47% 2 5% 14% 23% 9%	8402
February	1st to 10th	Night	42% 3 6% 20% 21% 7%	2730
	11th to 20th	Night	41% 3 7% 21% 20% 7%	2517
	21st to end	Night	37% 3 7% 17% 23% 12%	1961
March	1st to 10th	Night	44% 3 5% 14% 19% 16%	5029
	11th to 20th	Night	31% 4 5% 20% 17% 23%	5090
	21st to end	Night	39% 3 9% 20% 25% 4	5588
April	1st to 10th	Night	36% 4 9% 20% 19% 11%	2293
	11th to 20th	Night	35% 5% 8% 20% 21% 11%	2075
	21st to end	Night	36% 6% 10% 23% 22% 4	2063
May	1st to 10th	Night	45% 5% 10% 24% 12% 4	4170
	11th to 20th	Night	35% 5% 14% 23% 20% 3	4144
	21st to end	Night	38% 6% 16% 20% 13% 7%	4551
June	1st to 10th	Night	25% 6% 15% 30% 20% 3	1800
	11th to 20th	Night	23% 5% 12% 32% 24% 4	1800
	21st to end	Night	18% 5% 14% 30% 29% 4	1800
July	1st to 10th	Night	30% 8% 19% 27% 13% 2	4035
	11th to 20th	Night	18% 5% 12% 40% 24% 2	4026
	21st to end	Night	24% 6% 15% 32% 21% 1	4320
August	1st to 10th	Night	13% 5% 11% 30% 34% 7%	2916
	11th to 20th	Night	18% 4 16% 38% 18% 5%	2915
	21st to end	Night	23% 6% 15% 30% 22% 3	3585
September	1st to 10th	Night	26% 5% 11% 23% 24% 11%	2128
	11th to 20th	Night	31% 6% 10% 25% 20% 9%	2200
	21st to end	Night	24% 4 9% 23% 27% 14%	2200
October	1st to 10th	Night	13% 3 6% 14% 29% 35%	3811
	11th to 20th	Night	18% 2 4 16% 38% 22%	3899
	21st to end	Night	28% 4 5% 27% 25% 12%	4252
November	1st to 10th	Night	30% 3 7% 21% 27% 12%	2460
	11th to 20th	Night	28% 3 8% 21% 27% 13%	2573
	21st to end	Night	37% 3 7% 19% 27% 7%	2730
December	1st to 10th	Night	35% 4 7% 26% 23% 5%	4380
	11th to 20th	Night	43% 2 4 16% 23% 11%	4947
	21st to end	Night	43% 2 7% 19% 23% 5%	6633

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	25% 18% 31% 22% 4	330
	11th to 20th	Day	20% 20% 39% 17% 3 1	330
	21st to end	Day	22% 19% 35% 17% 6% 1	363
February	1st to 10th	Day	30% 15% 34% 17% 4	330
	11th to 20th	Day	31% 22% 33% 11% 3	330
	21st to end	Day	31% 21% 33% 12% 3	273
March	1st to 10th	Day	25% 20% 34% 16% 5%	330
	11th to 20th	Day	27% 22% 36% 10% 4	330
	21st to end	Day	24% 18% 40% 15% 3	363
April	1st to 10th	Day	26% 18% 34% 16% 5% 1	346
	11th to 20th	Day	29% 15% 30% 20% 7%	532
	21st to end	Day	24% 17% 34% 18% 6% 1	571
May	1st to 10th	Day	18% 14% 34% 26% 7% 1	753
	11th to 20th	Day	17% 10% 30% 29% 12% 2	775
	21st to end	Day	14% 9% 29% 29% 15% 3	844
June	1st to 10th	Day	10% 5% 17% 36% 26% 5%	731
	11th to 20th	Day	9% 3 19% 41% 23% 5%	730
	21st to end	Day	5% 2 15% 36% 33% 9%	730
July	1st to 10th	Day	8% 2 13% 32% 35% 11%	721
	11th to 20th	Day	3 2 11% 34% 41% 10%	718
	21st to end	Day	5% 2 8% 36% 37% 13%	794
August	1st to 10th	Day	4 1 8% 39% 40% 8%	726
	11th to 20th	Day	9% 2 8% 38% 35% 7%	715
	21st to end	Day	8% 1 8% 28% 39% 15%	583
September	1st to 10th	Day	7% 2 9% 32% 41% 9%	398
	11th to 20th	Day	4 2 14% 32% 35% 12%	330
	21st to end	Day	12% 5% 15% 32% 25% 11%	330
October	1st to 10th	Day	5% 3 23% 39% 23% 7%	330
	11th to 20th	Day	13% 9% 29% 34% 12% 2	330
	21st to end	Day	27% 12% 25% 25% 11% 1	363
November	1st to 10th	Day	21% 10% 30% 26% 12% 1	330
	11th to 20th	Day	17% 13% 35% 26% 9% 1	330
	21st to end	Day	24% 18% 28% 22% 8% 1	330
December	1st to 10th	Day	24% 15% 32% 21% 8% 1	330
	11th to 20th	Day	28% 13% 34% 19% 5%	330
	21st to end	Day	23% 20% 35% 18% 4 1	363
January	1st to 10th	Night	19% 12% 34% 29% 6%	1050
	11th to 20th	Night	22% 13% 33% 26% 5%	1050
	21st to end	Night	21% 12% 34% 28% 5%	1155
February	1st to 10th	Night	23% 14% 33% 25% 4	1050
	11th to 20th	Night	25% 15% 33% 24% 3	882
	21st to end	Night	23% 15% 35% 23% 3	577
March	1st to 10th	Night	23% 12% 34% 28% 4	630
	11th to 20th	Night	20% 13% 35% 27% 5%	630
	21st to end	Night	18% 12% 39% 26% 5%	693
April	1st to 10th	Night	17% 14% 36% 27% 6%	630
	11th to 20th	Night	19% 12% 36% 23% 9%	623
	21st to end	Night	18% 10% 37% 25% 9% 1	630
May	1st to 10th	Night	14% 7% 35% 35% 8%	630
	11th to 20th	Night	12% 6% 32% 35% 13% 1	621
	21st to end	Night	12% 4 25% 36% 19% 2	683
June	1st to 10th	Night	5% 6% 16% 39% 31% 3	600
	11th to 20th	Night	7% 1 19% 50% 22% 2	600
	21st to end	Night	4 2 14% 38% 39% 5%	600
July	1st to 10th	Night	5% 1 10% 38% 41% 5%	585
	11th to 20th	Night	3 1 10% 39% 42% 5%	582
	21st to end	Night	3 1 7% 41% 40% 7%	657
August	1st to 10th	Night	4 1 8% 39% 46% 3	597
	11th to 20th	Night	6% 1 9% 42% 38% 4	594
	21st to end	Night	4 2 6% 41% 41% 6%	660
September	1st to 10th	Night	8% 1 9% 40% 39% 4	600
	11th to 20th	Night	11% 2 10% 38% 37% 3	600
	21st to end	Night	7% 3 18% 37% 31% 4	600
October	1st to 10th	Night	9% 2 18% 43% 26% 2	730
	11th to 20th	Night	14% 6% 25% 38% 16% 1	800
	21st to end	Night	20% 8% 28% 28% 15% 1	880
November	1st to 10th	Night	16% 6% 29% 36% 12%	820
	11th to 20th	Night	14% 11% 31% 35% 10%	893
	21st to end	Night	22% 11% 29% 27% 10%	1050
December	1st to 10th	Night	20% 10% 30% 33% 6%	1050
	11th to 20th	Night	23% 11% 31% 30% 6%	1050
	21st to end	Night	23% 11% 32% 28% 7%	1155

Page generated at 2026-05-29 00:53:25. Version ac07

Copyright © 2026 Attilla Danko.