Potawatomi Wildlife Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Potawatomi Wildlife Park clear sky chart from 2005-11-06 to 2025-10-19.

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	13% 10% 4 8% 5% 5% 5% 4 6% 7% 35%	126299
	Night	15% 10% 4 8% 5% 4 4 3 5% 6% 35%	123612
Transparency	Day	47% 6% 12% 22% 13% 1	129866
	Night	48% 5% 11% 21% 14% 1	128119
Seeing	Day	17% 10% 27% 24% 16% 6%	17030
	Night	19% 9% 29% 29% 13% 1	26811

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	12% 14% 9% 18% 6% 4 4 4 5% 6% 18%	3617
	11th to 20th	Day	13% 15% 8% 13% 7% 7% 5% 5% 6% 4 15%	3620
	21st to end	Day	22% 18% 7% 11% 4 4 4 3 3 4 21%	4005
February	1st to 10th	Day	15% 16% 6% 11% 7% 5% 6% 4 4 4 23%	1948
	11th to 20th	Day	15% 13% 5% 12% 7% 5% 4 4 5% 5% 25%	1948
	21st to end	Day	16% 15% 6% 10% 4 4 4 4 5% 6% 26%	1650
March	1st to 10th	Day	18% 13% 6% 10% 5% 4 3 2 3 4 31%	4480
	11th to 20th	Day	10% 11% 5% 7% 4 4 4 3 5% 7% 39%	4796
	21st to end	Day	18% 14% 5% 11% 6% 5% 5% 4 5% 6% 22%	5726
April	1st to 10th	Day	17% 13% 4 8% 5% 4 4 4 4 6% 31%	2400
	11th to 20th	Day	17% 10% 3 6% 5% 5% 4 4 5% 6% 35%	2378
	21st to end	Day	18% 9% 3 7% 4 5% 4 4 5% 7% 34%	2600
May	1st to 10th	Day	19% 9% 3 8% 4 5% 5% 4 6% 8% 30%	5862
	11th to 20th	Day	15% 7% 2 6% 5% 4 5% 3 6% 8% 38%	5861
	21st to end	Day	14% 6% 2 6% 4 4 5% 3 6% 9% 40%	6790
June	1st to 10th	Day	11% 6% 2 6% 5% 5% 6% 4 6% 7% 43%	2800
	11th to 20th	Day	9% 6% 2 5% 5% 5% 5% 4 7% 8% 44%	2800
	21st to end	Day	11% 5% 2 6% 5% 5% 6% 5% 6% 9% 41%	2800
July	1st to 10th	Day	10% 5% 3 6% 5% 5% 5% 4 7% 10% 41%	6360
	11th to 20th	Day	8% 5% 2 6% 5% 5% 5% 5% 8% 11% 41%	6360
	21st to end	Day	10% 7% 3 7% 5% 5% 5% 4 6% 9% 39%	6881
August	1st to 10th	Day	8% 5% 2 6% 4 5% 5% 4 6% 9% 47%	4234
	11th to 20th	Day	9% 5% 2 6% 4 5% 5% 4 7% 8% 45%	4082
	21st to end	Day	6% 5% 2 5% 4 4 5% 4 6% 10% 48%	4312
September	1st to 10th	Day	10% 6% 2 6% 5% 4 4 4 5% 7% 47%	2375
	11th to 20th	Day	10% 5% 2 5% 4 4 5% 4 7% 8% 49%	2200
	21st to end	Day	12% 7% 3 6% 4 4 4 4 6% 7% 43%	2200
October	1st to 10th	Day	13% 7% 2 6% 4 4 4 3 5% 7% 45%	2200
	11th to 20th	Day	16% 8% 2 7% 4 4 3 4 6% 6% 39%	1974
	21st to end	Day	19% 11% 3 8% 5% 5% 4 4 5% 7% 28%	1881
November	1st to 10th	Day	11% 9% 3 6% 4 4 4 4 5% 7% 44%	1762
	11th to 20th	Day	17% 14% 3 9% 6% 3 4 3 4 7% 30%	1800
	21st to end	Day	19% 14% 4 10% 4 4 4 3 5% 5% 27%	1800
December	1st to 10th	Day	10% 14% 4 12% 5% 4 4 3 4 7% 32%	2807
	11th to 20th	Day	15% 16% 8% 13% 5% 4 4 3 4 5% 22%	3008
	21st to end	Day	28% 19% 7% 12% 6% 4 4 3 3 4 10%	3982
January	1st to 10th	Night	15% 15% 7% 16% 7% 4 5% 3 5% 5% 19%	6348
	11th to 20th	Night	13% 19% 8% 15% 7% 5% 5% 3 4 4 17%	6360
	21st to end	Night	20% 14% 7% 10% 5% 4 4 3 4 4 26%	6969
February	1st to 10th	Night	19% 13% 5% 9% 6% 4 4 3 5% 5% 26%	2450
	11th to 20th	Night	14% 13% 4 8% 7% 5% 4 3 5% 5% 31%	2338
	21st to end	Night	20% 12% 3 9% 5% 5% 4 3 4 6% 30%	1980
March	1st to 10th	Night	16% 11% 5% 8% 5% 4 4 3 4 6% 35%	5373
	11th to 20th	Night	12% 7% 3 6% 4 5% 4 4 6% 7% 42%	5149
	21st to end	Night	18% 10% 4 8% 4 4 4 3 5% 6% 33%	5247
April	1st to 10th	Night	15% 9% 3 7% 5% 4 4 4 6% 7% 36%	2000
	11th to 20th	Night	19% 7% 3 6% 4 4 4 3 6% 6% 38%	1970
	21st to end	Night	17% 8% 3 7% 4 4 4 4 6% 6% 37%	1800
May	1st to 10th	Night	20% 10% 3 7% 5% 4 4 3 5% 6% 31%	4033
	11th to 20th	Night	16% 8% 2 6% 4 3 3 3 6% 9% 39%	4032
	21st to end	Night	15% 8% 2 7% 4 4 4 3 5% 7% 40%	4077
June	1st to 10th	Night	10% 5% 3 5% 4 5% 4 2 6% 9% 48%	1600
	11th to 20th	Night	9% 6% 3 6% 4 4 4 4 5% 9% 46%	1600
	21st to end	Night	10% 5% 2 6% 5% 4 5% 4 7% 10% 43%	1600
July	1st to 10th	Night	8% 5% 2 6% 5% 5% 4 4 6% 9% 46%	3618
	11th to 20th	Night	7% 5% 2 6% 4 4 5% 4 6% 11% 46%	3617
	21st to end	Night	9% 6% 2 7% 4 5% 5% 4 7% 8% 42%	3985
August	1st to 10th	Night	10% 5% 2 6% 4 4 4 5% 7% 9% 45%	2915
	11th to 20th	Night	8% 5% 2 5% 4 5% 5% 4 7% 8% 49%	2964
	21st to end	Night	8% 4 2 6% 4 4 4 4 6% 8% 51%	3586
September	1st to 10th	Night	11% 5% 2 5% 3 4 3 3 4 7% 53%	2005
	11th to 20th	Night	8% 4 2 4 2 3 3 3 5% 8% 57%	2200
	21st to end	Night	12% 8% 3 5% 4 4 4 3 5% 6% 48%	2200
October	1st to 10th	Night	11% 5% 2 6% 3 4 4 3 5% 6% 51%	2200
	11th to 20th	Night	15% 9% 3 6% 4 4 4 3 5% 6% 42%	2376
	21st to end	Night	19% 9% 3 6% 4 4 4 4 5% 6% 37%	2717
November	1st to 10th	Night	13% 9% 3 7% 4 3 3 3 6% 6% 43%	2536
	11th to 20th	Night	15% 13% 3 8% 4 4 4 4 5% 7% 33%	2600
	21st to end	Night	18% 14% 4 8% 5% 5% 4 3 5% 6% 28%	2600
December	1st to 10th	Night	12% 10% 4 9% 5% 5% 4 4 6% 7% 33%	4372
	11th to 20th	Night	17% 16% 8% 12% 6% 5% 4 3 4 4 20%	5199
	21st to end	Night	26% 19% 6% 11% 5% 5% 4 3 4 4 12%	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	64% 5% 11% 15% 4	3618
	11th to 20th	Day	68% 4 10% 8% 9% 2	3620
	21st to end	Day	68% 3 9% 13% 6%	4005
February	1st to 10th	Day	65% 4 10% 13% 7% 1	1948
	11th to 20th	Day	59% 5% 10% 18% 7% 1	1958
	21st to end	Day	58% 5% 12% 16% 7% 1	1650
March	1st to 10th	Day	58% 4 7% 21% 9%	4480
	11th to 20th	Day	43% 4 12% 32% 8% 1	4796
	21st to end	Day	62% 6% 11% 15% 4 1	5728
April	1st to 10th	Day	54% 5% 11% 19% 11%	2400
	11th to 20th	Day	49% 6% 10% 22% 11% 2	2378
	21st to end	Day	49% 6% 12% 20% 11% 2	2600
May	1st to 10th	Day	51% 7% 11% 19% 12% 1	5897
	11th to 20th	Day	44% 7% 13% 23% 12% 1	5865
	21st to end	Day	40% 6% 11% 25% 16% 1	6804
June	1st to 10th	Day	38% 7% 11% 25% 17% 3	2800
	11th to 20th	Day	36% 6% 11% 26% 18% 3	2800
	21st to end	Day	40% 7% 14% 20% 16% 3	2800
July	1st to 10th	Day	37% 6% 12% 26% 17% 2	6291
	11th to 20th	Day	34% 8% 16% 26% 15% 1	6285
	21st to end	Day	40% 7% 13% 22% 16% 2	6685
August	1st to 10th	Day	34% 7% 15% 28% 15% 1	4221
	11th to 20th	Day	33% 8% 13% 28% 17% 1	4121
	21st to end	Day	30% 7% 14% 26% 20% 3	4311
September	1st to 10th	Day	35% 6% 14% 24% 18% 3	2375
	11th to 20th	Day	32% 6% 11% 27% 23% 2	2200
	21st to end	Day	40% 5% 10% 23% 20% 2	2200
October	1st to 10th	Day	28% 4 10% 33% 24% 1	3590
	11th to 20th	Day	37% 6% 9% 21% 26% 1	3203
	21st to end	Day	45% 5% 10% 26% 12% 2	3081
November	1st to 10th	Day	40% 6% 12% 24% 16% 1	1762
	11th to 20th	Day	55% 4 10% 18% 11% 2	1800
	21st to end	Day	58% 4 13% 18% 6% 1	1800
December	1st to 10th	Day	53% 4 16% 22% 5%	2807
	11th to 20th	Day	65% 4 12% 15% 4	3005
	21st to end	Day	79% 3 6% 8% 3	3982
January	1st to 10th	Night	65% 5% 10% 15% 5%	6348
	11th to 20th	Night	71% 3 8% 8% 9%	6360
	21st to end	Night	63% 3 11% 15% 8%	6969
February	1st to 10th	Night	60% 5% 11% 14% 8% 2	2450
	11th to 20th	Night	55% 4 10% 19% 11% 1	2339
	21st to end	Night	56% 4 12% 16% 10% 2	1980
March	1st to 10th	Night	50% 4 10% 27% 8% 1	5373
	11th to 20th	Night	40% 5% 13% 28% 13% 2	5149
	21st to end	Night	51% 5% 11% 23% 10% 1	5247
April	1st to 10th	Night	45% 6% 11% 21% 15% 1	2000
	11th to 20th	Night	45% 5% 10% 20% 17% 2	1970
	21st to end	Night	46% 5% 11% 22% 13% 3	1800
May	1st to 10th	Night	53% 6% 8% 17% 13% 2	4060
	11th to 20th	Night	42% 7% 11% 26% 14% 1	4033
	21st to end	Night	43% 6% 11% 21% 18% 2	4085
June	1st to 10th	Night	32% 6% 12% 28% 19% 4	1600
	11th to 20th	Night	36% 6% 12% 24% 19% 3	1600
	21st to end	Night	36% 7% 17% 21% 16% 3	1600
July	1st to 10th	Night	34% 6% 11% 28% 16% 4	3580
	11th to 20th	Night	32% 7% 17% 22% 20% 2	3572
	21st to end	Night	37% 7% 15% 20% 18% 3	3870
August	1st to 10th	Night	34% 8% 14% 29% 14% 1	2904
	11th to 20th	Night	30% 7% 13% 30% 19% 1	2991
	21st to end	Night	31% 6% 11% 27% 22% 3	3586
September	1st to 10th	Night	32% 5% 12% 26% 20% 5%	2005
	11th to 20th	Night	26% 5% 8% 30% 28% 3	2200
	21st to end	Night	38% 6% 10% 23% 22% 2	2200
October	1st to 10th	Night	23% 4 8% 32% 31% 1	3590
	11th to 20th	Night	35% 4 8% 23% 29% 1	3886
	21st to end	Night	37% 4 10% 27% 21% 1	4467
November	1st to 10th	Night	41% 5% 10% 24% 18% 2	2536
	11th to 20th	Night	50% 4 11% 20% 13% 2	2600
	21st to end	Night	57% 4 11% 20% 7%	2600
December	1st to 10th	Night	48% 6% 14% 26% 6%	4372
	11th to 20th	Night	67% 4 12% 10% 6% 1	5201
	21st to end	Night	75% 5% 9% 8% 3	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	20% 17% 37% 19% 6% 1	300
	11th to 20th	Day	22% 15% 42% 17% 3 1	300
	21st to end	Day	28% 16% 32% 19% 4	330
February	1st to 10th	Day	23% 18% 37% 17% 4 1	300
	11th to 20th	Day	28% 18% 33% 16% 4	300
	21st to end	Day	24% 20% 42% 10% 4	249
March	1st to 10th	Day	20% 21% 39% 18% 2	300
	11th to 20th	Day	24% 15% 33% 22% 7% 1	420
	21st to end	Day	31% 17% 27% 19% 6% 1	550
April	1st to 10th	Day	25% 13% 34% 20% 7% 1	500
	11th to 20th	Day	21% 17% 30% 19% 9% 3	492
	21st to end	Day	26% 13% 30% 20% 9% 2	500
May	1st to 10th	Day	23% 13% 29% 21% 11% 2	503
	11th to 20th	Day	21% 7% 28% 24% 17% 5%	527
	21st to end	Day	14% 5% 29% 26% 17% 9%	722
June	1st to 10th	Day	12% 8% 28% 26% 19% 6%	730
	11th to 20th	Day	11% 7% 29% 27% 20% 6%	730
	21st to end	Day	15% 6% 25% 30% 18% 7%	730
July	1st to 10th	Day	12% 3 18% 28% 23% 16%	721
	11th to 20th	Day	8% 4 24% 30% 23% 12%	718
	21st to end	Day	9% 4 19% 30% 28% 10%	776
August	1st to 10th	Day	7% 2 13% 29% 32% 16%	526
	11th to 20th	Day	11% 3 18% 28% 27% 12%	519
	21st to end	Day	8% 3 14% 29% 32% 14%	583
September	1st to 10th	Day	12% 5% 18% 27% 25% 12%	530
	11th to 20th	Day	8% 5% 13% 26% 30% 18%	530
	21st to end	Day	16% 9% 21% 23% 23% 9%	530
October	1st to 10th	Day	13% 5% 27% 29% 19% 8%	530
	11th to 20th	Day	18% 17% 24% 29% 10% 1	424
	21st to end	Day	29% 12% 34% 21% 4 1	330
November	1st to 10th	Day	12% 15% 33% 26% 10% 4	300
	11th to 20th	Day	24% 17% 32% 18% 9%	300
	21st to end	Day	30% 12% 36% 17% 5%	300
December	1st to 10th	Day	19% 18% 39% 16% 9%	300
	11th to 20th	Day	19% 18% 41% 16% 6% 1	300
	21st to end	Day	28% 18% 36% 16% 2	330
January	1st to 10th	Night	23% 16% 35% 21% 5%	1000
	11th to 20th	Night	24% 15% 37% 20% 3 1	1000
	21st to end	Night	22% 14% 36% 24% 4	1086
February	1st to 10th	Night	26% 11% 36% 24% 4	800
	11th to 20th	Night	21% 13% 38% 24% 3	783
	21st to end	Night	27% 13% 37% 18% 3	660
March	1st to 10th	Night	20% 12% 36% 26% 6% 1	800
	11th to 20th	Night	18% 13% 37% 27% 5% 1	800
	21st to end	Night	26% 10% 31% 27% 5%	789
April	1st to 10th	Night	19% 13% 36% 26% 6% 1	600
	11th to 20th	Night	21% 10% 35% 27% 7% 1	593
	21st to end	Night	21% 11% 33% 26% 10% 1	600
May	1st to 10th	Night	21% 7% 33% 29% 9% 1	600
	11th to 20th	Night	20% 4 29% 31% 14% 1	591
	21st to end	Night	13% 4 23% 41% 17% 1	650
June	1st to 10th	Night	12% 4 24% 45% 16% 1	600
	11th to 20th	Night	11% 3 26% 41% 19% 1	600
	21st to end	Night	12% 3 24% 37% 24% 2	600
July	1st to 10th	Night	8% 1 15% 43% 28% 5%	585
	11th to 20th	Night	11% 3 15% 40% 27% 3	582
	21st to end	Night	6% 3 13% 44% 32% 2	657
August	1st to 10th	Night	8% 1 10% 45% 32% 5%	597
	11th to 20th	Night	9% 3 14% 40% 30% 5%	594
	21st to end	Night	9% 2 13% 37% 35% 4	660
September	1st to 10th	Night	12% 3 17% 36% 29% 4	605
	11th to 20th	Night	10% 4 15% 35% 33% 4	800
	21st to end	Night	15% 6% 23% 32% 22% 3	800
October	1st to 10th	Night	13% 4 25% 35% 20% 3	800
	11th to 20th	Night	20% 12% 28% 30% 10%	793
	21st to end	Night	25% 11% 30% 26% 7%	836
November	1st to 10th	Night	18% 11% 34% 26% 11% 1	780
	11th to 20th	Night	22% 15% 34% 23% 5% 1	800
	21st to end	Night	26% 13% 32% 23% 6%	800
December	1st to 10th	Night	25% 15% 36% 20% 4	870
	11th to 20th	Night	24% 13% 36% 22% 5%	1000
	21st to end	Night	32% 13% 31% 21% 3	1100

Page generated at 2025-10-16 01:50:22. Version ac07

Copyright © 2025 Attilla Danko.