Torch Lake Township
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Torch Lake Township 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	14% 11% 5% 9% 5% 4 4 3 5% 6% 33%	101185
	Night	16% 14% 5% 11% 6% 4 4 3 4 5% 28%	97936
Transparency	Day	28% 46% 6% 13% 6%	104682
	Night	32% 46% 6% 10% 5%	102514
Seeing	Day	18% 9% 25% 27% 16% 5%	15700
	Night	21% 9% 26% 30% 12% 1	25403

By Month

Percentage Cloud Cover NE (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	14% 26% 17% 18% 6% 5% 3 2 2 2 5%	2527
	11th to 20th	Day	13% 19% 9% 23% 15% 6% 4 2 2 3 4	2530
	21st to end	Day	17% 25% 9% 16% 8% 5% 4 2 3 3 8%	2783
February	1st to 10th	Day	9% 18% 8% 16% 15% 6% 3 3 4 5% 13%	1621
	11th to 20th	Day	13% 16% 8% 15% 10% 5% 5% 3 3 6% 16%	1833
	21st to end	Day	12% 18% 7% 14% 7% 5% 5% 3 4 5% 21%	1570
March	1st to 10th	Day	14% 12% 4 9% 6% 4 3 4 6% 6% 33%	3118
	11th to 20th	Day	9% 14% 6% 14% 5% 5% 4 4 5% 6% 29%	3399
	21st to end	Day	17% 11% 9% 14% 6% 5% 4 3 4 5% 24%	3957
April	1st to 10th	Day	19% 14% 4 8% 5% 4 4 3 5% 6% 30%	2280
	11th to 20th	Day	19% 13% 4 6% 4 3 3 3 5% 5% 35%	2356
	21st to end	Day	16% 10% 4 8% 5% 4 4 4 5% 7% 34%	2470
May	1st to 10th	Day	14% 8% 2 7% 5% 4 4 3 5% 6% 42%	4108
	11th to 20th	Day	10% 7% 3 6% 4 4 4 3 5% 6% 48%	4234
	21st to end	Day	12% 7% 2 5% 4 3 5% 4 6% 8% 44%	4837
June	1st to 10th	Day	14% 5% 2 6% 4 4 4 3 7% 8% 43%	2779
	11th to 20th	Day	12% 6% 2 6% 4 4 4 5% 7% 8% 42%	2850
	21st to end	Day	15% 6% 2 5% 4 4 5% 4 6% 8% 42%	2766
July	1st to 10th	Day	18% 7% 2 5% 3 3 3 3 5% 9% 41%	4440
	11th to 20th	Day	9% 4 1 4 3 3 4 4 6% 9% 53%	4440
	21st to end	Day	9% 5% 2 5% 4 4 4 3 6% 10% 50%	4814
August	1st to 10th	Day	8% 6% 3 7% 5% 5% 5% 5% 7% 9% 42%	4245
	11th to 20th	Day	13% 6% 2 5% 4 4 4 3 4 7% 47%	4044
	21st to end	Day	14% 6% 3 6% 4 4 4 4 5% 6% 45%	4354
September	1st to 10th	Day	15% 5% 2 5% 4 4 4 4 6% 8% 44%	2252
	11th to 20th	Day	14% 5% 2 5% 4 4 4 4 5% 7% 46%	2090
	21st to end	Day	18% 5% 2 6% 4 4 5% 4 6% 8% 37%	2090
October	1st to 10th	Day	21% 8% 3 8% 5% 3 3 3 5% 8% 35%	2090
	11th to 20th	Day	24% 16% 4 10% 5% 5% 4 3 4 5% 19%	1795
	21st to end	Day	26% 18% 4 9% 5% 5% 4 3 5% 5% 16%	1881
November	1st to 10th	Day	18% 20% 4 8% 4 3 3 3 4 5% 26%	1699
	11th to 20th	Day	13% 29% 7% 13% 5% 4 4 2 4 5% 14%	1710
	21st to end	Day	19% 26% 10% 12% 3 4 3 3 4 4 13%	1561
December	1st to 10th	Day	17% 28% 13% 16% 6% 3 3 2 2 2 9%	1330
	11th to 20th	Day	15% 24% 9% 18% 8% 5% 4 2 3 3 8%	1671
	21st to end	Day	20% 23% 11% 16% 6% 5% 2 3 3 4 7%	2661
January	1st to 10th	Night	14% 26% 9% 20% 8% 4 2 2 2 3 9%	4428
	11th to 20th	Night	13% 18% 8% 22% 17% 5% 3 2 2 2 7%	4440
	21st to end	Night	16% 25% 9% 17% 9% 5% 3 2 3 3 7%	4884
February	1st to 10th	Night	11% 21% 6% 18% 13% 6% 3 3 2 4 13%	2557
	11th to 20th	Night	12% 15% 8% 18% 11% 5% 3 2 4 4 18%	2228
	21st to end	Night	15% 19% 5% 13% 7% 5% 4 2 4 5% 21%	1884
March	1st to 10th	Night	15% 12% 3 7% 4 3 3 3 4 6% 40%	3722
	11th to 20th	Night	9% 18% 5% 9% 5% 3 4 3 5% 5% 35%	3559
	21st to end	Night	16% 12% 6% 12% 5% 4 4 4 5% 6% 26%	3704
April	1st to 10th	Night	20% 12% 4 9% 6% 4 4 4 5% 6% 28%	1900
	11th to 20th	Night	20% 11% 3 7% 5% 4 4 4 3 6% 34%	1771
	21st to end	Night	17% 11% 3 6% 5% 4 4 3 5% 6% 36%	1710
May	1st to 10th	Night	16% 8% 3 6% 4 5% 5% 4 5% 6% 40%	2833
	11th to 20th	Night	13% 8% 3 7% 4 4 5% 4 5% 7% 41%	2662
	21st to end	Night	19% 6% 2 5% 4 3 4 3 5% 7% 42%	2750
June	1st to 10th	Night	14% 6% 2 6% 5% 5% 4 4 4 8% 42%	1397
	11th to 20th	Night	12% 5% 2 6% 5% 4 4 4 7% 7% 44%	1330
	21st to end	Night	13% 7% 2 5% 4 3 4 4 5% 7% 45%	1408
July	1st to 10th	Night	15% 7% 3 6% 4 4 4 4 6% 8% 41%	2530
	11th to 20th	Night	9% 5% 1 5% 5% 3 5% 3 5% 7% 50%	2530
	21st to end	Night	9% 5% 2 6% 4 3 4 3 5% 8% 48%	2750
August	1st to 10th	Night	13% 5% 3 6% 5% 5% 4 3 5% 8% 41%	2686
	11th to 20th	Night	14% 4 2 5% 3 4 4 3 5% 8% 48%	2785
	21st to end	Night	13% 6% 2 6% 4 4 4 4 5% 7% 46%	3299
September	1st to 10th	Night	13% 6% 2 6% 4 3 3 4 4 8% 47%	1908
	11th to 20th	Night	15% 6% 2 6% 3 3 4 3 6% 7% 46%	2090
	21st to end	Night	18% 7% 3 6% 5% 4 4 3 5% 7% 36%	2090
October	1st to 10th	Night	20% 8% 3 7% 5% 4 3 3 5% 5% 37%	2090
	11th to 20th	Night	24% 14% 4 8% 4 5% 4 3 5% 5% 23%	2383
	21st to end	Night	27% 17% 3 8% 5% 4 4 3 3 4 21%	2717
November	1st to 10th	Night	19% 18% 4 9% 4 4 3 3 4 6% 26%	2452
	11th to 20th	Night	17% 26% 7% 11% 5% 4 4 3 3 4 17%	2470
	21st to end	Night	18% 28% 9% 11% 5% 4 4 3 3 3 13%	2614
December	1st to 10th	Night	15% 30% 12% 16% 5% 4 2 1 2 2 9%	2850
	11th to 20th	Night	15% 23% 10% 20% 7% 4 2 3 4 3 10%	3526
	21st to end	Night	24% 21% 10% 13% 6% 5% 4 3 3 3 9%	4999

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	60% 36% 3 1 1	2528
	11th to 20th	Day	59% 36% 2 2 1	2530
	21st to end	Day	51% 38% 8% 2 1	2783
February	1st to 10th	Day	28% 66% 3 3 1	1621
	11th to 20th	Day	25% 64% 4 5% 2	1843
	21st to end	Day	22% 65% 4 6% 2	1570
March	1st to 10th	Day	30% 41% 7% 15% 7%	3120
	11th to 20th	Day	36% 40% 8% 11% 4 1	3399
	21st to end	Day	43% 40% 4 8% 5% 1	3957
April	1st to 10th	Day	22% 65% 3 8% 3	2280
	11th to 20th	Day	18% 66% 3 7% 6% 1	2356
	21st to end	Day	16% 65% 4 7% 7% 1	2470
May	1st to 10th	Day	26% 40% 5% 16% 13% 1	4120
	11th to 20th	Day	22% 39% 6% 23% 10% 1	4238
	21st to end	Day	25% 39% 6% 14% 15% 1	4837
June	1st to 10th	Day	14% 65% 4 10% 6% 1	2779
	11th to 20th	Day	16% 66% 4 8% 6% 1	2850
	21st to end	Day	14% 64% 4 12% 5%	2766
July	1st to 10th	Day	31% 37% 10% 15% 7% 1	4371
	11th to 20th	Day	16% 37% 10% 28% 9% 1	4365
	21st to end	Day	19% 38% 7% 22% 14%	4662
August	1st to 10th	Day	22% 40% 9% 21% 9%	4230
	11th to 20th	Day	26% 38% 8% 21% 7%	4083
	21st to end	Day	26% 40% 8% 20% 5%	4353
September	1st to 10th	Day	17% 61% 5% 11% 5%	2252
	11th to 20th	Day	13% 60% 4 14% 7% 1	2090
	21st to end	Day	16% 61% 6% 12% 5%	2090
October	1st to 10th	Day	19% 38% 5% 23% 14%	3480
	11th to 20th	Day	34% 38% 6% 14% 8%	2946
	21st to end	Day	41% 39% 8% 11% 2	3081
November	1st to 10th	Day	31% 57% 4 6% 3	1699
	11th to 20th	Day	31% 60% 4 4 1	1710
	21st to end	Day	34% 59% 3 2 1	1561
December	1st to 10th	Day	35% 59% 3 2 1	1330
	11th to 20th	Day	45% 48% 4 2 1	1671
	21st to end	Day	52% 37% 7% 2 2	2661
January	1st to 10th	Night	56% 35% 5% 4 1	4428
	11th to 20th	Night	59% 35% 3 2 1	4440
	21st to end	Night	54% 38% 5% 2 1	4884
February	1st to 10th	Night	28% 65% 2 4 2	2557
	11th to 20th	Night	23% 64% 4 7% 2	2229
	21st to end	Night	21% 65% 4 6% 3	1884
March	1st to 10th	Night	28% 39% 12% 16% 5%	3733
	11th to 20th	Night	32% 39% 8% 15% 5%	3560
	21st to end	Night	40% 39% 6% 10% 4	3704
April	1st to 10th	Night	22% 65% 3 5% 4 1	1900
	11th to 20th	Night	20% 65% 2 7% 4 2	1771
	21st to end	Night	19% 64% 3 7% 5% 1	1710
May	1st to 10th	Night	27% 40% 6% 13% 12% 2	2840
	11th to 20th	Night	24% 40% 5% 21% 10%	2663
	21st to end	Night	28% 39% 8% 12% 10% 3	2751
June	1st to 10th	Night	16% 65% 3 9% 6%	1397
	11th to 20th	Night	15% 66% 4 9% 5% 1	1330
	21st to end	Night	15% 64% 4 10% 8% 1	1408
July	1st to 10th	Night	30% 37% 9% 13% 8% 3	2490
	11th to 20th	Night	20% 38% 9% 21% 11%	2482
	21st to end	Night	22% 37% 9% 16% 15% 1	2662
August	1st to 10th	Night	28% 39% 9% 15% 9% 1	2677
	11th to 20th	Night	25% 39% 9% 19% 8%	2812
	21st to end	Night	24% 39% 9% 16% 11%	3299
September	1st to 10th	Night	15% 61% 6% 11% 7%	1908
	11th to 20th	Night	15% 60% 5% 12% 8%	2090
	21st to end	Night	19% 60% 6% 10% 5%	2090
October	1st to 10th	Night	27% 39% 6% 20% 7%	3480
	11th to 20th	Night	30% 37% 7% 16% 9%	3958
	21st to end	Night	35% 38% 10% 14% 3	4467
November	1st to 10th	Night	31% 58% 4 5% 2	2452
	11th to 20th	Night	30% 59% 4 5% 2	2470
	21st to end	Night	33% 60% 4 2 1	2614
December	1st to 10th	Night	35% 59% 2 4	2850
	11th to 20th	Night	44% 49% 5% 2 1	3525
	21st to end	Night	53% 37% 7% 2 1	4999

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% 14% 32% 24% 9% 2	270
	11th to 20th	Day	22% 13% 34% 24% 4 2	270
	21st to end	Day	23% 10% 29% 29% 7% 1	297
February	1st to 10th	Day	19% 20% 34% 20% 5% 2	270
	11th to 20th	Day	16% 17% 39% 21% 6%	270
	21st to end	Day	16% 22% 40% 20% 3	225
March	1st to 10th	Day	20% 14% 36% 23% 7%	270
	11th to 20th	Day	17% 13% 27% 30% 11% 2	405
	21st to end	Day	26% 10% 26% 25% 13% 1	506
April	1st to 10th	Day	23% 13% 28% 26% 9% 1	460
	11th to 20th	Day	25% 16% 23% 22% 10% 4	452
	21st to end	Day	19% 10% 26% 28% 15% 2	460
May	1st to 10th	Day	20% 11% 25% 26% 15% 3	463
	11th to 20th	Day	15% 6% 27% 31% 17% 5%	575
	21st to end	Day	12% 8% 25% 31% 19% 6%	734
June	1st to 10th	Day	14% 6% 26% 31% 19% 5%	680
	11th to 20th	Day	14% 6% 24% 33% 18% 4	680
	21st to end	Day	16% 4 23% 31% 21% 4	680
July	1st to 10th	Day	9% 3 21% 34% 24% 10%	671
	11th to 20th	Day	11% 5% 19% 34% 23% 8%	668
	21st to end	Day	9% 4 20% 35% 25% 7%	739
August	1st to 10th	Day	10% 3 17% 32% 27% 11%	576
	11th to 20th	Day	13% 3 16% 29% 26% 13%	479
	21st to end	Day	17% 5% 17% 30% 22% 9%	539
September	1st to 10th	Day	17% 7% 19% 24% 23% 10%	490
	11th to 20th	Day	14% 6% 15% 28% 27% 11%	490
	21st to end	Day	19% 9% 16% 26% 23% 7%	490
October	1st to 10th	Day	22% 9% 23% 27% 13% 6%	490
	11th to 20th	Day	29% 13% 26% 23% 8% 1	375
	21st to end	Day	29% 14% 29% 21% 5% 2	330
November	1st to 10th	Day	27% 16% 26% 19% 11% 1	279
	11th to 20th	Day	22% 20% 36% 16% 6%	270
	21st to end	Day	27% 18% 36% 16% 4	222
December	1st to 10th	Day	32% 17% 26% 19% 6% 1	180
	11th to 20th	Day	24% 22% 29% 19% 4 1	180
	21st to end	Day	29% 17% 33% 18% 2 1	265
January	1st to 10th	Night	23% 14% 33% 23% 6% 1	950
	11th to 20th	Night	25% 15% 30% 23% 7% 1	950
	21st to end	Night	22% 9% 32% 28% 8% 1	1045
February	1st to 10th	Night	18% 12% 32% 30% 7% 1	847
	11th to 20th	Night	19% 13% 34% 26% 7%	743
	21st to end	Night	24% 13% 31% 27% 5%	628
March	1st to 10th	Night	17% 10% 31% 30% 12% 1	760
	11th to 20th	Night	16% 11% 35% 31% 7% 1	760
	21st to end	Night	21% 7% 28% 33% 10% 1	774
April	1st to 10th	Night	25% 9% 28% 30% 8% 1	570
	11th to 20th	Night	23% 12% 23% 31% 11% 1	563
	21st to end	Night	20% 6% 25% 36% 11% 1	570
May	1st to 10th	Night	17% 6% 25% 36% 15% 1	570
	11th to 20th	Night	18% 4 22% 38% 17% 1	561
	21st to end	Night	17% 3 19% 38% 21% 3	617
June	1st to 10th	Night	14% 4 21% 40% 19% 1	447
	11th to 20th	Night	11% 4 21% 43% 20% 1	380
	21st to end	Night	12% 4 21% 39% 22% 2	458
July	1st to 10th	Night	12% 2 12% 44% 28% 3	555
	11th to 20th	Night	11% 2 16% 39% 28% 3	552
	21st to end	Night	10% 2 18% 40% 28% 3	624
August	1st to 10th	Night	11% 2 13% 43% 29% 2	567
	11th to 20th	Night	12% 4 13% 36% 31% 5%	564
	21st to end	Night	16% 4 15% 39% 23% 2	627
September	1st to 10th	Night	16% 3 18% 35% 24% 4	578
	11th to 20th	Night	17% 4 17% 33% 25% 4	760
	21st to end	Night	21% 8% 17% 31% 19% 4	760
October	1st to 10th	Night	24% 7% 21% 31% 16% 1	760
	11th to 20th	Night	31% 12% 23% 27% 7% 1	760
	21st to end	Night	37% 11% 22% 23% 6%	836
November	1st to 10th	Night	28% 11% 26% 28% 6% 1	755
	11th to 20th	Night	30% 15% 31% 20% 4	760
	21st to end	Night	31% 15% 30% 21% 4	807
December	1st to 10th	Night	28% 19% 30% 20% 3	950
	11th to 20th	Night	26% 13% 36% 20% 4 1	950
	21st to end	Night	30% 12% 34% 22% 3	1045

Page generated at 2024-11-01 22:47:46. Version ac07

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