Taum Sauk Mountain State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Taum Sauk Mountain State Park clear sky chart from 2005-11-06 to 2026-06-16.

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	12% 8% 3 6% 4 4 4 4 6% 7% 43%	137425
	Night	13% 8% 3 6% 4 4 4 3 5% 6% 44%	134840
Transparency	Day	38% 6% 11% 24% 17% 3	141021
	Night	38% 6% 11% 24% 18% 4	139324
Seeing	Day	18% 14% 28% 23% 13% 3	17709
	Night	18% 14% 29% 26% 12% 2	27545

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% 10% 3 7% 4 5% 4 3 5% 5% 41%	4723
	11th to 20th	Day	8% 7% 3 7% 4 3 4 3 5% 6% 50%	5310
	21st to end	Day	16% 8% 3 7% 4 4 4 3 4 5% 43%	5812
February	1st to 10th	Day	17% 10% 3 7% 5% 3 4 3 4 6% 37%	1890
	11th to 20th	Day	16% 9% 3 7% 3 3 3 4 6% 5% 39%	2039
	21st to end	Day	14% 11% 3 7% 4 4 4 4 6% 6% 39%	1730
March	1st to 10th	Day	16% 12% 3 6% 3 3 3 2 4 4 43%	4721
	11th to 20th	Day	10% 7% 2 5% 3 3 3 3 5% 6% 53%	5090
	21st to end	Day	14% 7% 3 7% 4 4 4 4 6% 8% 40%	5852
April	1st to 10th	Day	13% 7% 3 6% 4 4 4 3 5% 8% 44%	2520
	11th to 20th	Day	15% 10% 3 6% 4 4 4 3 5% 7% 39%	2494
	21st to end	Day	18% 8% 2 7% 4 4 4 3 6% 7% 37%	2520
May	1st to 10th	Day	13% 7% 3 8% 5% 6% 6% 4 7% 8% 34%	7021
	11th to 20th	Day	15% 9% 3 8% 4 5% 4 3 5% 7% 36%	8003
	21st to end	Day	19% 10% 3 8% 5% 4 4 4 5% 6% 32%	9047
June	1st to 10th	Day	9% 7% 2 6% 5% 5% 5% 4 6% 9% 42%	2940
	11th to 20th	Day	7% 4 2 6% 5% 5% 6% 4 7% 9% 47%	2871
	21st to end	Day	5% 4 2 5% 5% 5% 5% 5% 8% 10% 46%	2800
July	1st to 10th	Day	9% 4 2 7% 5% 4 5% 4 6% 8% 45%	6360
	11th to 20th	Day	5% 4 2 6% 5% 5% 5% 5% 7% 11% 43%	6282
	21st to end	Day	6% 5% 2 7% 5% 5% 7% 5% 8% 11% 38%	6422
August	1st to 10th	Day	5% 3 1 4 4 5% 4 5% 7% 9% 53%	4183
	11th to 20th	Day	11% 5% 2 7% 5% 4 5% 4 6% 8% 43%	3849
	21st to end	Day	7% 5% 2 5% 4 4 4 4 5% 9% 52%	4312
September	1st to 10th	Day	12% 5% 2 5% 3 3 5% 4 5% 7% 49%	2400
	11th to 20th	Day	10% 5% 2 6% 5% 4 4 4 6% 9% 46%	2386
	21st to end	Day	11% 6% 2 5% 3 3 4 3 5% 7% 52%	2177
October	1st to 10th	Day	9% 4 1 6% 3 4 4 3 5% 6% 57%	2000
	11th to 20th	Day	12% 7% 2 4 3 4 3 2 4 5% 53%	2000
	21st to end	Day	19% 8% 2 5% 3 3 3 3 4 5% 46%	2200
November	1st to 10th	Day	12% 6% 2 5% 4 4 4 2 4 5% 53%	1885
	11th to 20th	Day	13% 7% 3 6% 4 3 4 3 5% 6% 46%	1890
	21st to end	Day	17% 11% 3 6% 3 3 3 2 4 5% 43%	1848
December	1st to 10th	Day	9% 10% 3 7% 3 3 3 3 4 6% 50%	2690
	11th to 20th	Day	14% 11% 4 7% 3 3 4 3 4 6% 41%	3088
	21st to end	Day	19% 20% 4 8% 4 4 4 3 4 4 27%	4070
January	1st to 10th	Night	14% 10% 5% 9% 5% 4 4 3 4 4 38%	8195
	11th to 20th	Night	9% 8% 3 9% 4 4 4 3 4 5% 47%	7680
	21st to end	Night	16% 9% 4 7% 5% 4 4 3 4 5% 39%	8402
February	1st to 10th	Night	17% 10% 4 7% 4 4 3 3 4 6% 38%	2730
	11th to 20th	Night	16% 8% 4 7% 4 4 3 2 4 6% 42%	2465
	21st to end	Night	16% 8% 2 6% 4 4 4 3 5% 5% 42%	2076
March	1st to 10th	Night	17% 12% 3 7% 4 3 3 3 4 4 40%	5381
	11th to 20th	Night	12% 9% 2 6% 4 4 4 3 5% 5% 47%	5090
	21st to end	Night	14% 9% 3 7% 5% 4 4 4 5% 7% 38%	5318
April	1st to 10th	Night	11% 6% 2 5% 3 4 4 3 6% 8% 48%	2100
	11th to 20th	Night	14% 7% 3 6% 4 4 4 3 4 6% 44%	2075
	21st to end	Night	18% 8% 2 6% 4 4 3 3 4 5% 41%	2100
May	1st to 10th	Night	15% 8% 3 7% 5% 4 5% 4 7% 7% 36%	5832
	11th to 20th	Night	13% 7% 3 6% 4 4 4 3 5% 8% 41%	4846
	21st to end	Night	19% 11% 4 8% 5% 4 5% 4 5% 7% 30%	5139
June	1st to 10th	Night	9% 5% 2 5% 4 4 5% 5% 5% 9% 48%	1680
	11th to 20th	Night	7% 4 1 4 3 3 3 3 6% 10% 55%	1640
	21st to end	Night	4 2 1 4 3 4 5% 5% 7% 9% 57%	1600
July	1st to 10th	Night	9% 4 2 5% 4 4 4 3 6% 10% 48%	3618
	11th to 20th	Night	5% 4 2 5% 4 4 5% 4 6% 9% 52%	3677
	21st to end	Night	7% 4 2 6% 4 5% 5% 4 7% 11% 45%	4449
August	1st to 10th	Night	4 3 1 3 3 4 5% 4 6% 9% 58%	2972
	11th to 20th	Night	8% 6% 2 6% 4 3 4 4 5% 9% 48%	3200
	21st to end	Night	5% 4 2 4 3 3 4 4 6% 7% 58%	3586
September	1st to 10th	Night	10% 6% 2 5% 4 4 4 3 4 7% 52%	2000
	11th to 20th	Night	7% 6% 2 5% 4 4 4 3 5% 7% 53%	2000
	21st to end	Night	9% 5% 1 5% 3 4 4 3 6% 7% 53%	2212
October	1st to 10th	Night	6% 4 1 3 3 3 3 3 4 5% 64%	2400
	11th to 20th	Night	13% 6% 1 4 3 2 2 3 4 5% 56%	2400
	21st to end	Night	19% 7% 2 4 3 3 3 3 4 4 47%	2640
November	1st to 10th	Night	10% 6% 2 5% 3 2 3 2 4 7% 56%	2631
	11th to 20th	Night	13% 7% 2 5% 3 3 4 3 5% 5% 50%	2730
	21st to end	Night	18% 9% 3 6% 4 3 2 2 3 5% 45%	2767
December	1st to 10th	Night	12% 10% 2 6% 4 4 4 3 4 6% 46%	4720
	11th to 20th	Night	15% 9% 3 7% 4 4 3 3 4 6% 43%	5339
	21st to end	Night	21% 17% 4 8% 4 4 3 3 4 4 27%	7150

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	43% 5% 12% 26% 12% 3	4724
	11th to 20th	Day	35% 4 7% 29% 20% 6%	5310
	21st to end	Day	44% 3 9% 18% 16% 10%	5812
February	1st to 10th	Day	48% 5% 12% 21% 13% 2	1890
	11th to 20th	Day	45% 5% 11% 19% 14% 5%	2049
	21st to end	Day	44% 5% 8% 23% 14% 6%	1730
March	1st to 10th	Day	44% 5% 6% 20% 16% 9%	4721
	11th to 20th	Day	31% 4 8% 27% 22% 8%	5090
	21st to end	Day	41% 6% 14% 27% 11% 1	5854
April	1st to 10th	Day	38% 6% 12% 24% 19% 2	2520
	11th to 20th	Day	45% 4 10% 20% 16% 4	2494
	21st to end	Day	46% 6% 12% 22% 14% 1	2520
May	1st to 10th	Day	45% 8% 11% 23% 13% 1	7056
	11th to 20th	Day	46% 7% 10% 19% 16% 1	8007
	21st to end	Day	50% 7% 9% 19% 13% 2	9061
June	1st to 10th	Day	36% 8% 13% 25% 16% 1	2940
	11th to 20th	Day	31% 7% 13% 26% 20% 3	2871
	21st to end	Day	28% 10% 19% 23% 16% 4	2800
July	1st to 10th	Day	34% 7% 11% 27% 18% 2	6291
	11th to 20th	Day	32% 9% 17% 30% 11% 1	6207
	21st to end	Day	36% 10% 15% 28% 11% 1	6240
August	1st to 10th	Day	24% 8% 15% 32% 20%	4169
	11th to 20th	Day	37% 6% 13% 26% 16% 2	3885
	21st to end	Day	28% 6% 14% 35% 14% 3	4311
September	1st to 10th	Day	32% 7% 13% 26% 18% 5%	2400
	11th to 20th	Day	34% 6% 10% 24% 24% 1	2386
	21st to end	Day	31% 6% 8% 26% 25% 3	2177
October	1st to 10th	Day	18% 4 5% 19% 44% 11%	3260
	11th to 20th	Day	23% 4 5% 21% 37% 10%	3240
	21st to end	Day	31% 3 6% 29% 25% 5%	3538
November	1st to 10th	Day	34% 4 10% 25% 21% 6%	1885
	11th to 20th	Day	37% 5% 8% 22% 21% 7%	1890
	21st to end	Day	45% 3 9% 24% 18% 2	1848
December	1st to 10th	Day	35% 4 8% 37% 15% 1	2690
	11th to 20th	Day	44% 4 8% 24% 18% 2	3085
	21st to end	Day	60% 5% 10% 13% 10% 2	4070
January	1st to 10th	Night	47% 5% 12% 23% 12% 1	8196
	11th to 20th	Night	38% 4 6% 24% 24% 4	7680
	21st to end	Night	46% 4 9% 20% 17% 3	8402
February	1st to 10th	Night	46% 5% 10% 22% 14% 2	2730
	11th to 20th	Night	44% 4 11% 22% 16% 3	2466
	21st to end	Night	43% 4 8% 22% 18% 5%	2076
March	1st to 10th	Night	47% 4 6% 20% 16% 6%	5381
	11th to 20th	Night	38% 6% 8% 21% 18% 9%	5090
	21st to end	Night	42% 7% 14% 25% 11% 1	5318
April	1st to 10th	Night	33% 5% 15% 25% 20% 3	2100
	11th to 20th	Night	40% 6% 10% 22% 17% 5%	2075
	21st to end	Night	44% 5% 10% 24% 15% 2	2100
May	1st to 10th	Night	42% 8% 16% 22% 10% 1	5862
	11th to 20th	Night	40% 7% 12% 25% 15% 2	4847
	21st to end	Night	52% 8% 9% 18% 10% 2	5149
June	1st to 10th	Night	32% 8% 14% 24% 20% 2	1680
	11th to 20th	Night	24% 6% 13% 32% 21% 4	1640
	21st to end	Night	20% 9% 17% 29% 18% 7%	1600
July	1st to 10th	Night	32% 7% 12% 27% 21% 2	3580
	11th to 20th	Night	28% 8% 16% 32% 14% 2	3632
	21st to end	Night	30% 8% 20% 28% 13% 1	4320
August	1st to 10th	Night	19% 9% 19% 30% 21% 1	2962
	11th to 20th	Night	33% 7% 16% 25% 16% 4	3230
	21st to end	Night	23% 6% 14% 37% 17% 3	3586
September	1st to 10th	Night	31% 7% 9% 27% 20% 5%	2000
	11th to 20th	Night	30% 7% 11% 26% 24% 2	2000
	21st to end	Night	29% 6% 10% 22% 28% 4	2212
October	1st to 10th	Night	14% 3 6% 16% 46% 14%	3920
	11th to 20th	Night	22% 3 7% 21% 33% 14%	3899
	21st to end	Night	31% 4 7% 26% 25% 7%	4252
November	1st to 10th	Night	30% 4 11% 27% 22% 5%	2631
	11th to 20th	Night	35% 4 8% 24% 22% 6%	2730
	21st to end	Night	43% 4 7% 25% 20% 2	2767
December	1st to 10th	Night	39% 5% 9% 29% 17% 1	4720
	11th to 20th	Night	42% 5% 11% 21% 20% 2	5341
	21st to end	Night	57% 7% 10% 17% 7% 1	7150

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	30% 22% 36% 10% 2	330
	11th to 20th	Day	33% 28% 30% 8% 1	330
	21st to end	Day	23% 35% 31% 11% 1	363
February	1st to 10th	Day	27% 27% 32% 12% 2	330
	11th to 20th	Day	35% 29% 28% 6% 2 1	330
	21st to end	Day	33% 25% 34% 7% 1	273
March	1st to 10th	Day	26% 25% 36% 11% 2	330
	11th to 20th	Day	35% 23% 32% 8% 2	330
	21st to end	Day	31% 25% 33% 9% 2	477
April	1st to 10th	Day	24% 21% 34% 16% 4	540
	11th to 20th	Day	30% 20% 30% 15% 4 1	532
	21st to end	Day	23% 19% 37% 15% 6% 1	540
May	1st to 10th	Day	20% 21% 34% 19% 5% 1	543
	11th to 20th	Day	21% 15% 31% 20% 11% 2	712
	21st to end	Day	17% 11% 33% 24% 10% 4	844
June	1st to 10th	Day	12% 8% 29% 26% 21% 5%	780
	11th to 20th	Day	8% 5% 25% 39% 19% 4	756
	21st to end	Day	5% 6% 33% 33% 18% 4	730
July	1st to 10th	Day	11% 4 19% 30% 27% 9%	721
	11th to 20th	Day	6% 3 22% 38% 25% 6%	718
	21st to end	Day	8% 4 18% 38% 25% 7%	794
August	1st to 10th	Day	9% 2 19% 40% 23% 6%	701
	11th to 20th	Day	12% 5% 20% 30% 27% 6%	519
	21st to end	Day	10% 3 19% 30% 27% 11%	583
September	1st to 10th	Day	11% 4 22% 34% 22% 8%	530
	11th to 20th	Day	11% 3 18% 31% 26% 10%	530
	21st to end	Day	16% 9% 24% 27% 18% 7%	507
October	1st to 10th	Day	11% 10% 34% 32% 9% 3	330
	11th to 20th	Day	21% 16% 36% 22% 5% 1	330
	21st to end	Day	32% 20% 30% 15% 3	363
November	1st to 10th	Day	19% 17% 38% 19% 6% 1	330
	11th to 20th	Day	22% 22% 31% 18% 6% 1	330
	21st to end	Day	34% 18% 27% 16% 4 1	330
December	1st to 10th	Day	23% 23% 35% 14% 4 2	330
	11th to 20th	Day	28% 24% 30% 15% 2 1	330
	21st to end	Day	32% 24% 33% 8% 2	363
January	1st to 10th	Night	22% 23% 35% 16% 3	1050
	11th to 20th	Night	26% 27% 32% 13% 3	1050
	21st to end	Night	22% 23% 37% 17% 1	1155
February	1st to 10th	Night	25% 21% 36% 17% 1	1050
	11th to 20th	Night	24% 23% 38% 14% 2	830
	21st to end	Night	24% 23% 35% 17% 1	692
March	1st to 10th	Night	27% 18% 36% 18% 2	793
	11th to 20th	Night	24% 18% 34% 22% 3	630
	21st to end	Night	26% 17% 33% 19% 4	693
April	1st to 10th	Night	15% 20% 38% 23% 3	630
	11th to 20th	Night	20% 18% 32% 24% 6%	623
	21st to end	Night	22% 15% 36% 21% 6%	630
May	1st to 10th	Night	19% 9% 36% 27% 9%	630
	11th to 20th	Night	20% 10% 30% 26% 12% 2	621
	21st to end	Night	14% 8% 26% 33% 16% 3	683
June	1st to 10th	Night	12% 5% 19% 38% 24% 2	630
	11th to 20th	Night	9% 2 22% 44% 21% 1	615
	21st to end	Night	4 3 24% 41% 26% 2	600
July	1st to 10th	Night	10% 2 11% 34% 34% 10%	585
	11th to 20th	Night	6% 2 15% 43% 28% 5%	582
	21st to end	Night	7% 2 14% 42% 32% 3	657
August	1st to 10th	Night	7% 2 15% 39% 33% 5%	597
	11th to 20th	Night	10% 1 16% 37% 32% 3	594
	21st to end	Night	8% 2 14% 34% 36% 6%	660
September	1st to 10th	Night	12% 3 14% 35% 32% 4	600
	11th to 20th	Night	10% 3 15% 35% 32% 6%	600
	21st to end	Night	12% 7% 25% 27% 26% 4	793
October	1st to 10th	Night	8% 7% 27% 34% 21% 4	800
	11th to 20th	Night	16% 13% 31% 26% 13% 1	800
	21st to end	Night	24% 15% 31% 22% 7%	880
November	1st to 10th	Night	13% 14% 38% 25% 9%	820
	11th to 20th	Night	20% 16% 32% 26% 6%	840
	21st to end	Night	27% 17% 32% 19% 6%	877
December	1st to 10th	Night	22% 19% 33% 21% 4	1050
	11th to 20th	Night	24% 16% 34% 22% 3	1050
	21st to end	Night	29% 20% 32% 18% 2	1155

Page generated at 2026-06-13 01:31:38. Version ac07

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