Caesar Creek State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Caesar Creek State Park clear sky chart from 2005-11-06 to 2026-10-29.

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% 9% 3 8% 5% 5% 5% 4 6% 8% 35%	149864
	Night	14% 10% 4 8% 5% 4 4 3 5% 7% 36%	142078
Transparency	Day	47% 4 11% 23% 13% 2	153504
	Night	47% 4 11% 22% 14% 2	146510
Seeing	Day	17% 9% 26% 24% 16% 7%	17999
	Night	18% 8% 27% 31% 15% 2	27449

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	17% 16% 7% 12% 5% 4 4 3 4 5% 23%	4858
	11th to 20th	Day	12% 14% 5% 16% 8% 6% 4 2 3 4 25%	5280
	21st to end	Day	19% 13% 6% 11% 7% 6% 6% 4 5% 5% 18%	5780
February	1st to 10th	Day	19% 14% 5% 10% 5% 5% 4 2 4 5% 26%	1961
	11th to 20th	Day	16% 12% 4 11% 7% 5% 4 3 5% 6% 27%	2048
	21st to end	Day	17% 14% 5% 9% 4 4 4 3 4 5% 31%	1730
March	1st to 10th	Day	17% 13% 7% 10% 5% 4 4 3 4 4 30%	4668
	11th to 20th	Day	13% 8% 3 7% 5% 4 4 4 5% 8% 39%	5090
	21st to end	Day	17% 10% 4 7% 5% 4 4 3 6% 7% 33%	5586
April	1st to 10th	Day	15% 11% 3 8% 5% 4 4 3 6% 7% 34%	2445
	11th to 20th	Day	15% 8% 3 7% 5% 5% 4 3 5% 6% 38%	2581
	21st to end	Day	17% 7% 3 7% 5% 4 5% 4 6% 7% 35%	2730
May	1st to 10th	Day	18% 9% 3 8% 5% 5% 5% 4 6% 7% 31%	7616
	11th to 20th	Day	17% 7% 3 7% 4 4 4 4 5% 8% 36%	7626
	21st to end	Day	17% 8% 3 7% 5% 5% 5% 4 7% 9% 29%	8391
June	1st to 10th	Day	12% 6% 3 7% 5% 4 6% 4 7% 8% 39%	2730
	11th to 20th	Day	9% 5% 2 7% 5% 5% 4 5% 7% 10% 41%	2897
	21st to end	Day	10% 6% 2 6% 5% 5% 5% 5% 7% 10% 39%	2940
July	1st to 10th	Day	9% 6% 2 7% 5% 5% 5% 4 6% 10% 41%	8280
	11th to 20th	Day	11% 6% 2 6% 5% 4 5% 5% 6% 11% 38%	7865
	21st to end	Day	9% 6% 3 7% 5% 5% 6% 6% 7% 9% 35%	8340
August	1st to 10th	Day	11% 7% 2 6% 5% 5% 5% 5% 7% 9% 38%	6014
	11th to 20th	Day	12% 7% 3 8% 5% 5% 6% 5% 8% 10% 32%	5951
	21st to end	Day	5% 4 2 5% 3 4 4 4 6% 10% 54%	6224
September	1st to 10th	Day	11% 5% 1 4 4 4 5% 4 5% 6% 50%	2370
	11th to 20th	Day	9% 5% 2 5% 4 4 4 4 6% 9% 49%	2310
	21st to end	Day	16% 7% 2 6% 4 3 3 3 5% 7% 45%	2310
October	1st to 10th	Day	11% 4 2 6% 4 4 4 3 5% 7% 50%	2310
	11th to 20th	Day	15% 7% 2 5% 4 3 4 3 5% 6% 47%	2105
	21st to end	Day	20% 8% 3 6% 4 4 3 3 4 7% 39%	2148
November	1st to 10th	Day	10% 7% 2 5% 5% 4 4 3 5% 7% 49%	1852
	11th to 20th	Day	14% 12% 5% 8% 4 4 5% 4 5% 6% 35%	1890
	21st to end	Day	18% 12% 4 8% 6% 3 3 2 4 6% 32%	1890
December	1st to 10th	Day	17% 11% 4 9% 5% 4 3 4 4 5% 34%	3020
	11th to 20th	Day	19% 16% 5% 10% 5% 4 4 4 4 4 24%	3463
	21st to end	Day	21% 20% 6% 11% 6% 4 4 3 4 5% 17%	4565
January	1st to 10th	Night	13% 16% 6% 13% 8% 6% 5% 3 5% 5% 19%	7869
	11th to 20th	Night	11% 15% 7% 16% 7% 5% 4 3 4 5% 22%	7680
	21st to end	Night	18% 13% 5% 9% 5% 6% 4 3 4 5% 30%	8401
February	1st to 10th	Night	20% 12% 5% 8% 5% 4 5% 3 4 5% 29%	2656
	11th to 20th	Night	17% 12% 4 9% 5% 4 4 4 4 6% 30%	2458
	21st to end	Night	20% 13% 5% 9% 4 3 3 3 4 5% 30%	2076
March	1st to 10th	Night	19% 13% 3 7% 4 4 4 3 4 5% 37%	5404
	11th to 20th	Night	11% 7% 3 6% 5% 4 5% 4 6% 8% 42%	5090
	21st to end	Night	18% 9% 4 8% 5% 5% 4 4 4 6% 34%	5588
April	1st to 10th	Night	16% 9% 3 6% 4 4 4 4 5% 7% 38%	2192
	11th to 20th	Night	14% 7% 2 6% 4 3 4 4 6% 8% 40%	1988
	21st to end	Night	16% 8% 3 7% 4 3 4 4 5% 8% 39%	1890
May	1st to 10th	Night	21% 8% 3 7% 5% 5% 4 4 6% 8% 29%	5237
	11th to 20th	Night	15% 6% 3 7% 5% 4 4 4 6% 8% 38%	5234
	21st to end	Night	16% 8% 3 7% 4 4 5% 4 7% 9% 35%	5761
June	1st to 10th	Night	8% 6% 2 5% 4 4 4 4 5% 8% 49%	1890
	11th to 20th	Night	9% 5% 2 5% 4 4 4 3 8% 11% 45%	1716
	21st to end	Night	6% 5% 1 4 5% 5% 6% 6% 8% 10% 44%	1680
July	1st to 10th	Night	9% 6% 2 6% 4 5% 4 4 6% 9% 45%	4708
	11th to 20th	Night	10% 6% 3 7% 4 4 5% 4 6% 8% 43%	5083
	21st to end	Night	9% 6% 2 7% 4 5% 6% 4 7% 10% 41%	5736
August	1st to 10th	Night	10% 8% 3 7% 5% 5% 5% 4 6% 8% 39%	4135
	11th to 20th	Night	13% 8% 3 8% 4 4 4 4 6% 8% 38%	4095
	21st to end	Night	3 3 1 5% 3 4 5% 4 7% 10% 56%	4884
September	1st to 10th	Night	12% 5% 2 4 3 4 4 3 5% 7% 53%	2227
	11th to 20th	Night	8% 4 1 5% 4 3 4 3 6% 7% 54%	2310
	21st to end	Night	14% 7% 2 5% 4 3 3 2 5% 6% 49%	2310
October	1st to 10th	Night	9% 5% 2 6% 4 4 3 3 5% 6% 54%	2310
	11th to 20th	Night	14% 7% 2 7% 4 3 3 3 5% 6% 45%	2514
	21st to end	Night	18% 7% 3 6% 4 4 4 3 5% 6% 40%	2865
November	1st to 10th	Night	13% 7% 2 6% 4 3 3 3 4 7% 46%	2666
	11th to 20th	Night	15% 9% 3 7% 4 4 5% 3 5% 6% 39%	2730
	21st to end	Night	19% 13% 4 7% 5% 4 4 3 5% 7% 30%	2730
December	1st to 10th	Night	16% 11% 4 10% 4 4 3 3 5% 5% 35%	4380
	11th to 20th	Night	18% 15% 7% 9% 5% 4 4 3 4 5% 25%	4952
	21st to end	Night	21% 19% 6% 11% 6% 4 4 3 4 5% 17%	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	65% 3 11% 16% 5%	4859
	11th to 20th	Day	65% 2 8% 12% 11% 1	5280
	21st to end	Day	69% 3 9% 12% 6% 1	5780
February	1st to 10th	Day	61% 4 9% 16% 9% 1	1961
	11th to 20th	Day	59% 4 11% 17% 8% 1	2058
	21st to end	Day	56% 5% 10% 19% 8% 1	1730
March	1st to 10th	Day	59% 3 6% 19% 11% 2	4668
	11th to 20th	Day	43% 4 10% 27% 15% 1	5090
	21st to end	Day	51% 4 12% 20% 10% 3	5586
April	1st to 10th	Day	49% 5% 11% 23% 11% 1	2445
	11th to 20th	Day	47% 5% 11% 21% 13% 3	2581
	21st to end	Day	48% 6% 11% 22% 11% 2	2730
May	1st to 10th	Day	53% 4 12% 21% 11%	7651
	11th to 20th	Day	47% 4 12% 25% 12%	7630
	21st to end	Day	49% 6% 11% 19% 12% 3	8405
June	1st to 10th	Day	41% 7% 12% 22% 16% 2	2730
	11th to 20th	Day	38% 7% 15% 23% 16% 2	2897
	21st to end	Day	39% 8% 16% 20% 15% 3	2940
July	1st to 10th	Day	40% 4 12% 27% 16% 1	8211
	11th to 20th	Day	40% 4 12% 32% 12%	7792
	21st to end	Day	43% 4 12% 23% 15% 3	8156
August	1st to 10th	Day	42% 4 14% 25% 12% 3	6001
	11th to 20th	Day	47% 4 11% 26% 11%	5990
	21st to end	Day	27% 4 16% 34% 18% 2	6223
September	1st to 10th	Day	33% 6% 10% 26% 21% 5%	2370
	11th to 20th	Day	33% 4 11% 26% 23% 3	2310
	21st to end	Day	40% 4 10% 21% 23% 2	2310
October	1st to 10th	Day	25% 4 9% 30% 31% 2	3700
	11th to 20th	Day	31% 3 9% 30% 26% 2	3345
	21st to end	Day	37% 2 11% 24% 23% 3	3398
November	1st to 10th	Day	36% 4 10% 28% 19% 3	1852
	11th to 20th	Day	51% 3 10% 19% 15% 2	1890
	21st to end	Day	54% 4 9% 22% 10% 1	1890
December	1st to 10th	Day	53% 2 10% 26% 8%	3020
	11th to 20th	Day	64% 4 9% 17% 6%	3460
	21st to end	Day	71% 4 10% 11% 5%	4565
January	1st to 10th	Night	67% 3 10% 14% 7%	7870
	11th to 20th	Night	66% 3 7% 13% 10% 2	7680
	21st to end	Night	58% 2 11% 20% 8% 1	8401
February	1st to 10th	Night	59% 4 9% 19% 8% 1	2656
	11th to 20th	Night	55% 4 10% 19% 11% 1	2459
	21st to end	Night	57% 4 11% 16% 10% 2	2076
March	1st to 10th	Night	51% 4 7% 26% 11% 2	5404
	11th to 20th	Night	40% 5% 11% 29% 13% 1	5090
	21st to end	Night	51% 4 8% 24% 12% 1	5588
April	1st to 10th	Night	45% 5% 13% 24% 11% 2	2192
	11th to 20th	Night	41% 5% 14% 18% 18% 4	1988
	21st to end	Night	44% 5% 11% 24% 13% 3	1890
May	1st to 10th	Night	54% 4 9% 22% 8% 3	5264
	11th to 20th	Night	44% 5% 12% 25% 14% 1	5235
	21st to end	Night	45% 5% 14% 21% 10% 5%	5771
June	1st to 10th	Night	34% 6% 11% 26% 22% 2	1890
	11th to 20th	Night	31% 7% 17% 22% 19% 4	1716
	21st to end	Night	32% 8% 17% 21% 17% 4	1680
July	1st to 10th	Night	38% 4 13% 25% 17% 3	4670
	11th to 20th	Night	38% 4 12% 33% 13% 1	5036
	21st to end	Night	38% 3 13% 25% 18% 3	5606
August	1st to 10th	Night	43% 5% 12% 24% 13% 3	4124
	11th to 20th	Night	45% 4 13% 23% 14%	4122
	21st to end	Night	25% 3 17% 33% 20% 2	4884
September	1st to 10th	Night	31% 5% 13% 25% 20% 6%	2227
	11th to 20th	Night	28% 5% 10% 26% 27% 3	2310
	21st to end	Night	37% 4 10% 20% 26% 3	2310
October	1st to 10th	Night	23% 3 7% 29% 35% 3	3700
	11th to 20th	Night	31% 3 9% 26% 30% 3	4013
	21st to end	Night	35% 2 8% 24% 26% 5%	4565
November	1st to 10th	Night	38% 4 12% 23% 21% 3	2666
	11th to 20th	Night	45% 4 9% 23% 16% 3	2730
	21st to end	Night	56% 4 11% 19% 9% 1	2730
December	1st to 10th	Night	52% 3 11% 24% 9%	4380
	11th to 20th	Night	62% 3 11% 17% 7%	4954
	21st to end	Night	72% 3 8% 14% 3	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	24% 16% 37% 17% 5%	330
	11th to 20th	Day	25% 23% 36% 13% 3	330
	21st to end	Day	30% 18% 31% 17% 4	363
February	1st to 10th	Day	25% 15% 36% 20% 4	330
	11th to 20th	Day	26% 21% 35% 15% 3	330
	21st to end	Day	23% 17% 47% 12% 2	273
March	1st to 10th	Day	23% 18% 39% 17% 4	366
	11th to 20th	Day	23% 15% 36% 19% 7% 1	540
	21st to end	Day	25% 16% 35% 19% 5%	594
April	1st to 10th	Day	21% 16% 33% 20% 8% 2	540
	11th to 20th	Day	20% 17% 27% 23% 10% 3	532
	21st to end	Day	21% 10% 34% 22% 10% 2	540
May	1st to 10th	Day	23% 13% 32% 22% 8% 3	543
	11th to 20th	Day	21% 8% 27% 24% 14% 7%	567
	21st to end	Day	16% 5% 23% 28% 18% 10%	617
June	1st to 10th	Day	13% 4 21% 31% 22% 9%	570
	11th to 20th	Day	10% 6% 21% 32% 23% 7%	737
	21st to end	Day	11% 4 23% 31% 21% 9%	780
July	1st to 10th	Day	12% 3 14% 25% 27% 18%	771
	11th to 20th	Day	11% 3 18% 26% 27% 15%	628
	21st to end	Day	11% 2 15% 30% 27% 15%	620
August	1st to 10th	Day	10% 2 14% 25% 30% 19%	566
	11th to 20th	Day	12% 4 16% 30% 25% 14%	559
	21st to end	Day	8% 3 12% 26% 33% 17%	627
September	1st to 10th	Day	11% 3 14% 25% 32% 15%	570
	11th to 20th	Day	9% 3 11% 26% 35% 17%	570
	21st to end	Day	20% 8% 17% 23% 22% 10%	570
October	1st to 10th	Day	10% 4 21% 34% 21% 10%	570
	11th to 20th	Day	15% 10% 29% 25% 15% 6%	570
	21st to end	Day	21% 11% 34% 24% 8% 2	483
November	1st to 10th	Day	15% 10% 34% 25% 11% 5%	330
	11th to 20th	Day	20% 18% 30% 20% 9% 2	330
	21st to end	Day	25% 13% 38% 21% 4	330
December	1st to 10th	Day	20% 18% 38% 17% 6% 1	330
	11th to 20th	Day	23% 13% 42% 18% 5%	330
	21st to end	Day	30% 18% 33% 15% 4	363
January	1st to 10th	Night	21% 16% 35% 22% 6%	932
	11th to 20th	Night	26% 15% 36% 20% 3	840
	21st to end	Night	22% 12% 39% 24% 3	924
February	1st to 10th	Night	26% 9% 35% 27% 3	840
	11th to 20th	Night	24% 13% 36% 25% 2	823
	21st to end	Night	26% 11% 39% 22% 2	692
March	1st to 10th	Night	21% 12% 35% 26% 5%	840
	11th to 20th	Night	20% 14% 34% 26% 6%	840
	21st to end	Night	23% 11% 32% 27% 7%	924
April	1st to 10th	Night	20% 11% 33% 30% 5% 1	722
	11th to 20th	Night	17% 9% 34% 29% 10% 1	623
	21st to end	Night	18% 7% 37% 28% 9% 1	630
May	1st to 10th	Night	21% 7% 31% 28% 11% 1	630
	11th to 20th	Night	17% 4 26% 34% 16% 3	621
	21st to end	Night	11% 3 20% 36% 25% 4	683
June	1st to 10th	Night	10% 2 19% 44% 23% 1	630
	11th to 20th	Night	10% 3 16% 43% 26% 2	630
	21st to end	Night	8% 2 19% 42% 26% 2	630
July	1st to 10th	Night	10% 2 9% 36% 34% 8%	615
	11th to 20th	Night	8% 2 10% 39% 35% 5%	612
	21st to end	Night	10% 1 11% 40% 34% 3	690
August	1st to 10th	Night	8% 2 11% 39% 36% 4	627
	11th to 20th	Night	11% 1 10% 42% 32% 5%	624
	21st to end	Night	7% 2 11% 34% 40% 7%	693
September	1st to 10th	Night	13% 2 13% 33% 34% 5%	757
	11th to 20th	Night	10% 3 11% 35% 37% 5%	840
	21st to end	Night	17% 4 18% 36% 23% 2	840
October	1st to 10th	Night	11% 4 22% 36% 22% 5%	840
	11th to 20th	Night	18% 8% 26% 34% 14% 1	840
	21st to end	Night	20% 7% 32% 28% 12%	913
November	1st to 10th	Night	17% 7% 30% 30% 15% 1	820
	11th to 20th	Night	18% 13% 32% 28% 8% 1	840
	21st to end	Night	25% 11% 27% 30% 7%	840
December	1st to 10th	Night	25% 11% 33% 25% 5%	840
	11th to 20th	Night	26% 9% 35% 25% 5% 1	840
	21st to end	Night	29% 13% 30% 25% 3	924

Page generated at 2026-10-26 04:37:52. Version ac07

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