Kettle Moraine North
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Kettle Moraine North clear sky chart from 2005-11-06 to 2024-11-04.

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% 9% 3 8% 5% 4 5% 4 6% 7% 38%	101408
	Night	13% 9% 3 8% 5% 4 4 4 5% 7% 38%	97683
Transparency	Day	43% 6% 12% 24% 13% 1	104953
	Night	44% 6% 12% 23% 14% 2	102279
Seeing	Day	16% 12% 31% 25% 12% 4	15925
	Night	17% 10% 32% 28% 11% 1	25769

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% 12% 6% 11% 6% 5% 5% 4 5% 5% 29%	2527
	11th to 20th	Day	11% 12% 5% 14% 6% 5% 6% 7% 6% 6% 21%	2530
	21st to end	Day	18% 17% 8% 12% 4 4 3 3 3 5% 22%	2783
February	1st to 10th	Day	11% 13% 5% 10% 5% 4 4 5% 5% 7% 32%	1701
	11th to 20th	Day	12% 11% 4 8% 5% 4 5% 4 5% 6% 36%	1833
	21st to end	Day	11% 15% 4 9% 5% 3 5% 4 5% 6% 32%	1570
March	1st to 10th	Day	13% 9% 3 6% 4 3 4 3 5% 6% 43%	3120
	11th to 20th	Day	10% 8% 3 8% 5% 6% 4 3 5% 6% 42%	3270
	21st to end	Day	22% 12% 4 10% 5% 3 4 3 4 4 29%	4165
April	1st to 10th	Day	17% 13% 4 8% 4 5% 4 3 5% 6% 31%	2280
	11th to 20th	Day	18% 11% 3 7% 4 4 4 3 5% 7% 34%	2254
	21st to end	Day	18% 10% 3 8% 5% 4 5% 3 6% 6% 33%	2418
May	1st to 10th	Day	13% 8% 3 7% 4 5% 4 4 5% 7% 40%	4131
	11th to 20th	Day	12% 5% 2 6% 5% 5% 4 3 5% 7% 45%	4399
	21st to end	Day	12% 6% 2 7% 5% 4 4 4 7% 9% 40%	4824
June	1st to 10th	Day	10% 6% 2 6% 5% 5% 4 4 6% 8% 44%	2660
	11th to 20th	Day	11% 5% 2 7% 5% 4 5% 4 6% 8% 42%	2660
	21st to end	Day	9% 6% 2 7% 4 4 5% 4 6% 10% 43%	2660
July	1st to 10th	Day	13% 6% 3 7% 5% 5% 5% 4 8% 10% 35%	4440
	11th to 20th	Day	5% 3 2 4 4 4 6% 5% 7% 10% 50%	4440
	21st to end	Day	8% 5% 2 6% 5% 4 4 4 7% 9% 46%	4813
August	1st to 10th	Day	9% 6% 2 7% 5% 5% 6% 5% 7% 8% 41%	4423
	11th to 20th	Day	12% 5% 2 5% 5% 5% 5% 4 7% 8% 43%	3842
	21st to end	Day	10% 6% 3 7% 4 5% 5% 4 6% 8% 43%	4180
September	1st to 10th	Day	11% 6% 2 7% 4 5% 4 4 5% 8% 44%	2280
	11th to 20th	Day	11% 5% 2 5% 4 4 4 3 6% 7% 48%	2170
	21st to end	Day	13% 7% 2 5% 5% 5% 4 4 5% 7% 42%	2090
October	1st to 10th	Day	14% 6% 2 6% 4 3 4 4 5% 7% 43%	2014
	11th to 20th	Day	21% 8% 2 7% 5% 5% 5% 4 6% 7% 30%	1862
	21st to end	Day	16% 10% 3 9% 5% 4 4 4 5% 6% 35%	1881
November	1st to 10th	Day	11% 9% 3 7% 4 3 4 3 5% 7% 42%	1699
	11th to 20th	Day	10% 11% 4 10% 7% 5% 5% 4 6% 8% 31%	1710
	21st to end	Day	17% 10% 4 7% 6% 4 4 3 5% 6% 36%	1558
December	1st to 10th	Day	13% 11% 5% 9% 5% 5% 7% 4 5% 8% 28%	1520
	11th to 20th	Day	11% 15% 5% 8% 6% 4 6% 4 6% 8% 28%	1918
	21st to end	Day	18% 20% 8% 13% 5% 3 3 3 4 5% 17%	2783
January	1st to 10th	Night	14% 13% 6% 11% 5% 4 4 2 4 4 33%	4428
	11th to 20th	Night	12% 12% 6% 14% 6% 5% 6% 6% 6% 6% 21%	4440
	21st to end	Night	15% 16% 7% 11% 6% 4 4 3 4 5% 25%	4884
February	1st to 10th	Night	12% 13% 4 9% 5% 5% 4 3 5% 6% 35%	2475
	11th to 20th	Night	11% 9% 3 8% 6% 5% 5% 4 5% 5% 39%	2232
	21st to end	Night	16% 13% 4 6% 5% 4 4 4 5% 5% 35%	1884
March	1st to 10th	Night	15% 9% 3 6% 4 4 4 3 4 6% 43%	3733
	11th to 20th	Night	9% 7% 2 5% 5% 4 5% 5% 6% 8% 43%	3704
	21st to end	Night	19% 11% 4 11% 5% 4 4 3 4 5% 31%	3466
April	1st to 10th	Night	17% 11% 3 7% 4 4 3 4 5% 7% 35%	1900
	11th to 20th	Night	20% 8% 3 7% 4 4 4 3 4 6% 38%	1875
	21st to end	Night	16% 9% 3 6% 4 4 4 4 5% 6% 39%	1761
May	1st to 10th	Night	13% 7% 3 8% 5% 5% 5% 4 5% 7% 39%	2764
	11th to 20th	Night	12% 6% 2 8% 5% 4 5% 5% 6% 8% 40%	2506
	21st to end	Night	15% 9% 2 6% 5% 4 5% 4 4 6% 40%	2743
June	1st to 10th	Night	10% 5% 1 6% 3 4 4 4 6% 9% 47%	1520
	11th to 20th	Night	12% 4 2 5% 4 4 4 4 6% 9% 46%	1520
	21st to end	Night	9% 6% 2 7% 4 3 4 4 6% 7% 49%	1520
July	1st to 10th	Night	13% 7% 3 7% 3 4 4 4 5% 8% 41%	2530
	11th to 20th	Night	4 3 1 4 4 4 4 4 7% 9% 55%	2530
	21st to end	Night	6% 4 2 5% 4 4 5% 4 6% 8% 51%	2750
August	1st to 10th	Night	10% 5% 2 5% 4 4 3 4 6% 8% 48%	2517
	11th to 20th	Night	9% 6% 2 6% 5% 4 5% 4 5% 7% 47%	2984
	21st to end	Night	8% 5% 2 5% 4 4 5% 4 6% 9% 48%	3476
September	1st to 10th	Night	9% 5% 2 5% 4 3 3 3 5% 7% 54%	1900
	11th to 20th	Night	12% 4 2 4 2 3 4 3 6% 7% 53%	1990
	21st to end	Night	12% 7% 2 5% 4 3 4 3 5% 7% 48%	2090
October	1st to 10th	Night	11% 7% 2 7% 4 4 3 3 5% 6% 49%	2163
	11th to 20th	Night	15% 8% 2 7% 4 4 4 4 5% 7% 40%	2317
	21st to end	Night	17% 10% 3 6% 4 4 4 4 6% 7% 35%	2717
November	1st to 10th	Night	12% 7% 3 6% 5% 4 3 4 5% 6% 45%	2452
	11th to 20th	Night	14% 10% 4 9% 6% 5% 5% 4 5% 7% 33%	2470
	21st to end	Night	16% 10% 2 6% 5% 5% 5% 4 5% 6% 36%	2619
December	1st to 10th	Night	13% 12% 4 8% 6% 4 5% 4 6% 6% 31%	2660
	11th to 20th	Night	13% 13% 4 9% 6% 5% 4 4 5% 6% 29%	3279
	21st to end	Night	19% 19% 4 10% 6% 4 4 3 4 5% 21%	4884

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	57% 6% 15% 16% 6%	2528
	11th to 20th	Day	60% 5% 13% 17% 5%	2530
	21st to end	Day	66% 4 9% 16% 5%	2783
February	1st to 10th	Day	51% 5% 13% 20% 9% 1	1701
	11th to 20th	Day	49% 6% 10% 22% 12% 2	1843
	21st to end	Day	52% 5% 11% 19% 10% 3	1570
March	1st to 10th	Day	39% 8% 10% 25% 14% 4	3120
	11th to 20th	Day	41% 5% 12% 24% 16% 2	3270
	21st to end	Day	58% 6% 10% 18% 7% 1	4165
April	1st to 10th	Day	53% 7% 11% 19% 10%	2280
	11th to 20th	Day	51% 6% 8% 20% 13% 3	2254
	21st to end	Day	50% 7% 11% 18% 12% 1	2418
May	1st to 10th	Day	42% 7% 11% 22% 17% 1	4169
	11th to 20th	Day	38% 7% 10% 32% 13% 1	4403
	21st to end	Day	39% 8% 11% 22% 16% 3	4837
June	1st to 10th	Day	36% 7% 12% 27% 15% 2	2660
	11th to 20th	Day	38% 7% 13% 24% 16% 1	2660
	21st to end	Day	36% 8% 13% 25% 15% 2	2660
July	1st to 10th	Day	43% 8% 12% 25% 10% 2	4371
	11th to 20th	Day	25% 7% 17% 33% 16% 2	4365
	21st to end	Day	34% 8% 14% 21% 21% 2	4662
August	1st to 10th	Day	38% 7% 15% 27% 12% 1	4408
	11th to 20th	Day	37% 8% 12% 31% 11% 1	3881
	21st to end	Day	39% 6% 13% 24% 17% 1	4179
September	1st to 10th	Day	38% 7% 11% 27% 15% 1	2280
	11th to 20th	Day	34% 7% 13% 31% 14% 1	2170
	21st to end	Day	40% 5% 13% 29% 12%	2090
October	1st to 10th	Day	24% 4 7% 38% 25% 2	3352
	11th to 20th	Day	38% 5% 10% 24% 21% 1	3078
	21st to end	Day	43% 4 11% 26% 14% 1	3081
November	1st to 10th	Day	41% 5% 14% 24% 14% 2	1699
	11th to 20th	Day	51% 5% 14% 20% 8% 1	1710
	21st to end	Day	50% 4 15% 23% 7% 1	1558
December	1st to 10th	Day	53% 7% 16% 16% 7% 1	1520
	11th to 20th	Day	54% 4 17% 15% 8% 2	1915
	21st to end	Day	70% 4 10% 11% 5%	2783
January	1st to 10th	Night	55% 5% 9% 19% 10% 1	4428
	11th to 20th	Night	64% 5% 10% 13% 8%	4440
	21st to end	Night	62% 5% 11% 16% 6%	4884
February	1st to 10th	Night	51% 5% 10% 20% 12% 2	2475
	11th to 20th	Night	46% 5% 11% 23% 14% 2	2233
	21st to end	Night	49% 5% 12% 20% 12% 2	1884
March	1st to 10th	Night	43% 5% 13% 26% 10% 3	3733
	11th to 20th	Night	36% 6% 12% 24% 19% 2	3704
	21st to end	Night	56% 6% 7% 18% 11% 2	3466
April	1st to 10th	Night	48% 5% 10% 18% 17% 1	1900
	11th to 20th	Night	48% 5% 9% 19% 17% 3	1875
	21st to end	Night	45% 5% 12% 22% 14% 2	1761
May	1st to 10th	Night	44% 6% 11% 20% 16% 2	2791
	11th to 20th	Night	39% 9% 11% 27% 13% 1	2507
	21st to end	Night	44% 7% 10% 18% 15% 7%	2751
June	1st to 10th	Night	33% 7% 13% 29% 18% 1	1520
	11th to 20th	Night	34% 7% 11% 26% 19% 2	1520
	21st to end	Night	34% 7% 16% 24% 18% 2	1520
July	1st to 10th	Night	40% 6% 14% 21% 13% 5%	2490
	11th to 20th	Night	22% 7% 17% 32% 18% 2	2482
	21st to end	Night	29% 7% 16% 22% 23% 4	2662
August	1st to 10th	Night	32% 7% 15% 25% 19% 2	2508
	11th to 20th	Night	34% 7% 12% 30% 16%	3011
	21st to end	Night	31% 6% 14% 25% 21% 3	3476
September	1st to 10th	Night	31% 7% 10% 26% 25% 2	1900
	11th to 20th	Night	31% 5% 11% 35% 18% 1	1990
	21st to end	Night	36% 6% 10% 31% 16% 1	2090
October	1st to 10th	Night	26% 4 7% 39% 23% 1	3605
	11th to 20th	Night	33% 4 13% 28% 19% 3	3840
	21st to end	Night	43% 4 10% 25% 17%	4467
November	1st to 10th	Night	39% 5% 12% 25% 16% 2	2452
	11th to 20th	Night	50% 5% 14% 19% 11% 1	2470
	21st to end	Night	49% 5% 15% 22% 8% 1	2619
December	1st to 10th	Night	52% 6% 14% 19% 8% 1	2660
	11th to 20th	Night	55% 6% 12% 16% 9% 1	3281
	21st to end	Night	65% 5% 11% 14% 5%	4884

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	17% 17% 36% 23% 6% 1	270
	11th to 20th	Day	15% 21% 35% 23% 6%	270
	21st to end	Day	22% 12% 40% 21% 4 1	297
February	1st to 10th	Day	14% 22% 41% 17% 6% 1	270
	11th to 20th	Day	20% 25% 34% 16% 5%	270
	21st to end	Day	21% 24% 41% 13% 1	225
March	1st to 10th	Day	18% 26% 42% 11% 3	270
	11th to 20th	Day	23% 19% 33% 17% 6% 2	290
	21st to end	Day	27% 12% 32% 22% 6% 1	506
April	1st to 10th	Day	27% 12% 36% 19% 6%	460
	11th to 20th	Day	23% 20% 28% 17% 10% 2	452
	21st to end	Day	23% 14% 28% 23% 12% 1	460
May	1st to 10th	Day	20% 13% 34% 22% 8% 2	486
	11th to 20th	Day	16% 12% 32% 25% 11% 3	675
	21st to end	Day	16% 10% 29% 26% 14% 5%	734
June	1st to 10th	Day	11% 9% 33% 30% 12% 4	680
	11th to 20th	Day	14% 9% 32% 28% 13% 4	680
	21st to end	Day	13% 9% 32% 30% 12% 4	680
July	1st to 10th	Day	9% 5% 23% 31% 25% 9%	671
	11th to 20th	Day	8% 7% 28% 30% 20% 7%	668
	21st to end	Day	5% 4 31% 32% 21% 7%	739
August	1st to 10th	Day	8% 4 26% 34% 18% 9%	676
	11th to 20th	Day	14% 4 17% 30% 24% 12%	487
	21st to end	Day	13% 6% 23% 28% 21% 9%	539
September	1st to 10th	Day	12% 8% 26% 28% 19% 8%	490
	11th to 20th	Day	11% 5% 20% 34% 21% 9%	490
	21st to end	Day	18% 12% 26% 23% 16% 5%	490
October	1st to 10th	Day	18% 12% 27% 25% 15% 4	414
	11th to 20th	Day	20% 21% 32% 19% 7%	300
	21st to end	Day	25% 15% 39% 16% 4 1	330
November	1st to 10th	Day	17% 17% 34% 21% 8% 2	279
	11th to 20th	Day	16% 20% 40% 18% 6%	270
	21st to end	Day	23% 16% 39% 17% 6%	270
December	1st to 10th	Day	20% 18% 41% 15% 4 1	270
	11th to 20th	Day	22% 20% 37% 13% 6% 1	270
	21st to end	Day	25% 20% 35% 18% 1 1	297
January	1st to 10th	Night	17% 17% 38% 22% 6%	950
	11th to 20th	Night	20% 14% 38% 21% 6% 1	950
	21st to end	Night	19% 13% 38% 25% 6%	1045
February	1st to 10th	Night	19% 15% 36% 24% 5% 1	950
	11th to 20th	Night	15% 17% 37% 24% 5%	757
	21st to end	Night	24% 14% 38% 19% 4	628
March	1st to 10th	Night	20% 13% 35% 24% 8% 1	760
	11th to 20th	Night	15% 14% 39% 25% 7%	737
	21st to end	Night	21% 9% 30% 32% 7% 1	627
April	1st to 10th	Night	21% 11% 39% 22% 7%	570
	11th to 20th	Night	22% 12% 34% 25% 7% 1	563
	21st to end	Night	20% 10% 31% 29% 9% 1	570
May	1st to 10th	Night	18% 10% 33% 32% 6% 1	570
	11th to 20th	Night	18% 8% 30% 31% 12% 1	561
	21st to end	Night	15% 6% 24% 36% 18% 2	617
June	1st to 10th	Night	11% 6% 27% 39% 16% 1	570
	11th to 20th	Night	13% 5% 31% 36% 14% 2	570
	21st to end	Night	10% 5% 25% 42% 16% 1	570
July	1st to 10th	Night	9% 2 19% 41% 27% 3	555
	11th to 20th	Night	7% 2 25% 38% 26% 3	552
	21st to end	Night	6% 3 23% 42% 25% 2	624
August	1st to 10th	Night	7% 2 17% 45% 26% 3	567
	11th to 20th	Night	9% 2 16% 41% 26% 6%	564
	21st to end	Night	9% 2 21% 40% 24% 3	627
September	1st to 10th	Night	10% 4 24% 33% 25% 5%	570
	11th to 20th	Night	12% 4 22% 32% 25% 6%	660
	21st to end	Night	15% 8% 26% 27% 20% 3	760
October	1st to 10th	Night	14% 9% 28% 31% 17% 2	760
	11th to 20th	Night	19% 13% 33% 27% 8% 1	760
	21st to end	Night	22% 11% 33% 25% 9%	836
November	1st to 10th	Night	15% 12% 37% 25% 10% 1	755
	11th to 20th	Night	21% 18% 33% 22% 6%	760
	21st to end	Night	21% 13% 36% 22% 7%	909
December	1st to 10th	Night	20% 16% 37% 22% 5%	950
	11th to 20th	Night	22% 14% 39% 19% 5% 1	950
	21st to end	Night	27% 15% 36% 20% 3	1045

Page generated at 2024-11-01 21:47:36. Version ac07

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