Goshen College
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Goshen College clear sky chart from 2005-11-06 to 2024-07-05.

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% 10% 4 8% 5% 5% 4 4 6% 7% 33%	89347
	Night	16% 11% 4 8% 5% 4 4 4 5% 6% 33%	89922
Transparency	Day	49% 6% 12% 20% 12% 1	89102
	Night	51% 6% 11% 20% 12% 1	89773
Seeing	Day	19% 10% 27% 24% 14% 6%	15224
	Night	20% 9% 28% 29% 12% 1	25125

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	15% 17% 9% 12% 5% 5% 5% 4 5% 5% 17%	2527
	11th to 20th	Day	14% 18% 9% 12% 7% 6% 6% 5% 8% 6% 9%	2530
	21st to end	Day	27% 22% 9% 12% 4 3 2 2 3 4 13%	2813
February	1st to 10th	Day	16% 14% 6% 11% 7% 6% 4 3 6% 5% 21%	1824
	11th to 20th	Day	14% 12% 5% 13% 8% 6% 4 4 5% 6% 24%	1848
	21st to end	Day	16% 16% 6% 11% 5% 4 4 3 5% 5% 25%	1570
March	1st to 10th	Day	19% 14% 6% 8% 5% 5% 3 3 4 6% 26%	3120
	11th to 20th	Day	12% 9% 6% 8% 5% 4 5% 4 7% 9% 32%	3377
	21st to end	Day	19% 13% 6% 11% 6% 5% 4 3 5% 5% 23%	3963
April	1st to 10th	Day	17% 13% 4 8% 5% 4 4 3 5% 6% 30%	2280
	11th to 20th	Day	17% 9% 3 7% 5% 5% 4 4 4 7% 35%	2278
	21st to end	Day	18% 9% 3 7% 5% 4 4 3 6% 8% 34%	2470
May	1st to 10th	Day	19% 8% 3 7% 4 4 5% 4 5% 7% 33%	4082
	11th to 20th	Day	14% 8% 2 6% 4 5% 5% 4 7% 7% 38%	4081
	21st to end	Day	9% 5% 3 6% 4 4 5% 4 7% 9% 44%	4718
June	1st to 10th	Day	10% 6% 2 6% 5% 4 5% 5% 6% 9% 42%	2660
	11th to 20th	Day	9% 5% 2 5% 5% 5% 5% 5% 6% 7% 45%	2660
	21st to end	Day	11% 5% 2 6% 4 6% 6% 5% 7% 8% 40%	2660
July	1st to 10th	Day	8% 6% 2 6% 4 4 4 5% 6% 9% 46%	2577
	11th to 20th	Day	9% 5% 2 5% 4 4 4 4 7% 10% 45%	2520
	21st to end	Day	7% 4 2 5% 5% 5% 6% 5% 7% 9% 43%	2722
August	1st to 10th	Day	7% 4 2 6% 5% 5% 6% 4 7% 9% 46%	2327
	11th to 20th	Day	9% 5% 2 6% 5% 6% 5% 4 7% 10% 41%	2285
	21st to end	Day	9% 5% 1 6% 4 4 5% 4 5% 9% 48%	2376
September	1st to 10th	Day	11% 6% 3 6% 5% 5% 5% 3 5% 8% 44%	2129
	11th to 20th	Day	11% 5% 2 5% 4 4 4 4 6% 8% 46%	1980
	21st to end	Day	12% 6% 2 7% 4 4 4 4 5% 8% 43%	1980
October	1st to 10th	Day	14% 7% 3 6% 4 3 4 4 6% 7% 42%	1980
	11th to 20th	Day	19% 9% 2 7% 5% 4 4 4 5% 7% 34%	1792
	21st to end	Day	21% 11% 3 8% 5% 5% 4 4 5% 7% 26%	1782
November	1st to 10th	Day	12% 9% 3 7% 5% 4 4 4 5% 7% 41%	1672
	11th to 20th	Day	16% 16% 5% 7% 5% 4 4 3 5% 5% 30%	1710
	21st to end	Day	20% 15% 5% 10% 5% 5% 4 3 4 5% 25%	1710
December	1st to 10th	Day	15% 19% 7% 11% 6% 4 4 3 4 5% 22%	1643
	11th to 20th	Day	13% 19% 7% 12% 6% 5% 3 3 5% 5% 21%	1918
	21st to end	Day	22% 22% 7% 14% 6% 4 4 3 3 4 10%	2783
January	1st to 10th	Night	17% 17% 8% 12% 6% 5% 4 3 5% 5% 19%	4428
	11th to 20th	Night	15% 20% 8% 15% 6% 4 4 6% 6% 4 12%	4440
	21st to end	Night	26% 19% 8% 12% 5% 4 3 3 4 4 14%	4852
February	1st to 10th	Night	18% 15% 4 10% 7% 4 4 3 4 6% 25%	2354
	11th to 20th	Night	14% 13% 5% 11% 6% 5% 5% 3 5% 7% 27%	2218
	21st to end	Night	20% 13% 5% 10% 5% 5% 4 3 4 5% 26%	1884
March	1st to 10th	Night	16% 12% 4 8% 4 4 4 2 4 7% 34%	3733
	11th to 20th	Night	10% 8% 3 7% 6% 4 5% 3 5% 7% 41%	3581
	21st to end	Night	19% 10% 4 9% 5% 4 3 3 5% 6% 32%	3696
April	1st to 10th	Night	16% 11% 2 5% 4 4 5% 4 5% 8% 36%	1900
	11th to 20th	Night	19% 8% 3 6% 4 5% 4 3 5% 5% 37%	1851
	21st to end	Night	17% 10% 3 6% 5% 4 5% 4 5% 5% 36%	1710
May	1st to 10th	Night	16% 9% 2 7% 5% 5% 4 4 6% 8% 33%	2813
	11th to 20th	Night	18% 8% 3 6% 4 4 3 3 4 8% 40%	2812
	21st to end	Night	13% 6% 2 6% 4 4 4 4 5% 7% 44%	2842
June	1st to 10th	Night	9% 5% 2 5% 4 3 4 4 6% 9% 48%	1520
	11th to 20th	Night	8% 5% 2 6% 5% 4 5% 5% 6% 9% 45%	1520
	21st to end	Night	9% 6% 3 6% 5% 4 5% 4 7% 9% 43%	1520
July	1st to 10th	Night	6% 4 2 5% 4 5% 5% 4 7% 9% 50%	1477
	11th to 20th	Night	7% 4 2 5% 4 3 4 4 7% 8% 52%	1440
	21st to end	Night	6% 4 2 5% 4 4 5% 5% 6% 8% 51%	1593
August	1st to 10th	Night	6% 5% 2 5% 3 4 4 5% 7% 9% 50%	1611
	11th to 20th	Night	7% 4 2 5% 4 4 5% 4 7% 8% 50%	1612
	21st to end	Night	9% 5% 1 5% 3 4 4 3 6% 7% 53%	1980
September	1st to 10th	Night	12% 5% 2 5% 4 3 3 3 5% 6% 51%	1813
	11th to 20th	Night	10% 5% 2 5% 4 3 3 3 4 7% 54%	1980
	21st to end	Night	13% 6% 2 6% 3 3 3 3 5% 6% 48%	1980
October	1st to 10th	Night	13% 6% 3 5% 3 3 4 3 5% 6% 48%	1980
	11th to 20th	Night	18% 10% 3 5% 4 4 4 2 4 6% 38%	2165
	21st to end	Night	23% 9% 3 7% 4 3 4 3 3 6% 34%	2574
November	1st to 10th	Night	12% 11% 3 7% 4 5% 4 4 5% 6% 40%	2406
	11th to 20th	Night	15% 14% 4 9% 5% 3 4 5% 6% 7% 29%	2470
	21st to end	Night	19% 16% 4 8% 5% 4 4 3 5% 6% 26%	2470
December	1st to 10th	Night	17% 16% 6% 10% 6% 5% 4 3 5% 6% 21%	2534
	11th to 20th	Night	17% 17% 6% 12% 7% 5% 4 4 4 5% 20%	3279
	21st to end	Night	26% 19% 7% 10% 5% 4 4 3 4 5% 12%	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	66% 7% 11% 12% 4	2528
	11th to 20th	Day	71% 5% 10% 10% 4	2530
	21st to end	Day	78% 3 6% 10% 3	2813
February	1st to 10th	Day	64% 5% 10% 13% 7% 1	1824
	11th to 20th	Day	61% 6% 9% 16% 8%	1858
	21st to end	Day	61% 4 11% 16% 6% 2	1570
March	1st to 10th	Day	59% 4 10% 19% 7%	3120
	11th to 20th	Day	46% 7% 13% 26% 7% 1	3377
	21st to end	Day	62% 6% 11% 16% 4	3963
April	1st to 10th	Day	54% 5% 10% 19% 12%	2280
	11th to 20th	Day	49% 5% 11% 21% 12% 2	2278
	21st to end	Day	48% 5% 13% 19% 13% 2	2470
May	1st to 10th	Day	47% 7% 14% 22% 10%	4120
	11th to 20th	Day	42% 7% 15% 25% 10% 1	4085
	21st to end	Day	33% 7% 14% 22% 23% 1	4731
June	1st to 10th	Day	37% 6% 12% 26% 17% 2	2660
	11th to 20th	Day	35% 7% 11% 25% 19% 2	2660
	21st to end	Day	39% 8% 15% 19% 16% 3	2660
July	1st to 10th	Day	34% 7% 12% 24% 19% 4	2508
	11th to 20th	Day	32% 8% 14% 27% 16% 2	2445
	21st to end	Day	33% 9% 13% 25% 17% 3	2571
August	1st to 10th	Day	33% 7% 16% 28% 14% 2	2314
	11th to 20th	Day	36% 7% 15% 25% 15% 2	2285
	21st to end	Day	33% 6% 12% 25% 19% 5%	2376
September	1st to 10th	Day	37% 7% 15% 20% 17% 4	2129
	11th to 20th	Day	34% 6% 12% 28% 19% 1	1980
	21st to end	Day	38% 5% 12% 25% 19% 1	1980
October	1st to 10th	Day	41% 6% 11% 25% 16% 2	1980
	11th to 20th	Day	49% 5% 11% 21% 15%	1792
	21st to end	Day	57% 6% 12% 16% 9% 1	1782
November	1st to 10th	Day	43% 6% 11% 25% 15% 1	1672
	11th to 20th	Day	57% 3 10% 20% 9% 1	1710
	21st to end	Day	62% 4 11% 16% 6%	1710
December	1st to 10th	Day	65% 4 10% 15% 5%	1643
	11th to 20th	Day	64% 5% 12% 15% 3	1915
	21st to end	Day	79% 4 7% 6% 3	2783
January	1st to 10th	Night	65% 7% 9% 13% 5%	4428
	11th to 20th	Night	73% 5% 9% 10% 3	4440
	21st to end	Night	74% 4 8% 10% 3	4852
February	1st to 10th	Night	62% 4 11% 14% 8% 1	2354
	11th to 20th	Night	57% 5% 9% 20% 8% 1	2219
	21st to end	Night	61% 4 10% 15% 8% 2	1884
March	1st to 10th	Night	51% 5% 11% 24% 8% 1	3733
	11th to 20th	Night	39% 8% 11% 26% 14% 2	3581
	21st to end	Night	52% 6% 14% 20% 7% 1	3696
April	1st to 10th	Night	45% 6% 12% 21% 14% 1	1900
	11th to 20th	Night	49% 5% 8% 19% 17% 2	1851
	21st to end	Night	48% 6% 10% 20% 13% 2	1710
May	1st to 10th	Night	47% 7% 12% 22% 11% 1	2840
	11th to 20th	Night	42% 7% 11% 27% 12% 1	2813
	21st to end	Night	36% 8% 13% 20% 21% 2	2850
June	1st to 10th	Night	31% 7% 12% 29% 19% 3	1520
	11th to 20th	Night	35% 7% 13% 23% 20% 2	1520
	21st to end	Night	36% 6% 18% 22% 16% 3	1520
July	1st to 10th	Night	30% 7% 14% 24% 20% 5%	1437
	11th to 20th	Night	29% 6% 15% 27% 20% 3	1392
	21st to end	Night	29% 7% 14% 24% 20% 5%	1504
August	1st to 10th	Night	28% 8% 14% 30% 19% 1	1600
	11th to 20th	Night	31% 7% 16% 24% 20% 3	1612
	21st to end	Night	31% 6% 11% 25% 22% 5%	1980
September	1st to 10th	Night	34% 6% 12% 23% 19% 5%	1813
	11th to 20th	Night	30% 5% 8% 31% 24% 2	1980
	21st to end	Night	37% 5% 10% 28% 19% 2	1980
October	1st to 10th	Night	37% 6% 8% 28% 19% 1	1980
	11th to 20th	Night	46% 6% 9% 23% 15% 1	2165
	21st to end	Night	52% 5% 10% 20% 12% 1	2574
November	1st to 10th	Night	43% 7% 10% 23% 16% 1	2406
	11th to 20th	Night	51% 7% 12% 19% 9% 1	2470
	21st to end	Night	59% 4 11% 19% 7%	2470
December	1st to 10th	Night	63% 5% 10% 14% 7%	2534
	11th to 20th	Night	64% 6% 12% 12% 5% 1	3281
	21st to end	Night	74% 5% 10% 8% 3	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	21% 20% 32% 20% 6% 1	270
	11th to 20th	Day	26% 15% 37% 16% 5% 1	270
	21st to end	Day	29% 14% 33% 20% 4 1	297
February	1st to 10th	Day	27% 17% 34% 18% 4 1	270
	11th to 20th	Day	25% 19% 32% 20% 3 1	270
	21st to end	Day	27% 21% 39% 9% 4	225
March	1st to 10th	Day	24% 21% 34% 17% 4	270
	11th to 20th	Day	24% 14% 32% 21% 7% 1	396
	21st to end	Day	32% 14% 27% 19% 6% 1	506
April	1st to 10th	Day	26% 13% 31% 22% 7% 1	460
	11th to 20th	Day	23% 18% 30% 16% 9% 4	452
	21st to end	Day	25% 14% 31% 19% 10% 2	460
May	1st to 10th	Day	26% 13% 30% 19% 10% 3	463
	11th to 20th	Day	23% 8% 27% 24% 14% 5%	487
	21st to end	Day	13% 7% 27% 27% 17% 8%	667
June	1st to 10th	Day	10% 9% 28% 29% 17% 5%	680
	11th to 20th	Day	13% 7% 27% 29% 19% 5%	680
	21st to end	Day	14% 6% 30% 29% 16% 6%	680
July	1st to 10th	Day	10% 3 19% 29% 22% 17%	642
	11th to 20th	Day	11% 4 23% 29% 20% 12%	618
	21st to end	Day	9% 4 20% 32% 24% 11%	663
August	1st to 10th	Day	10% 2 16% 28% 26% 18%	446
	11th to 20th	Day	11% 5% 17% 33% 26% 9%	439
	21st to end	Day	13% 4 16% 29% 26% 12%	495
September	1st to 10th	Day	15% 6% 19% 27% 23% 10%	450
	11th to 20th	Day	10% 5% 17% 24% 31% 14%	450
	21st to end	Day	17% 10% 21% 24% 22% 8%	450
October	1st to 10th	Day	17% 6% 26% 27% 17% 7%	450
	11th to 20th	Day	24% 17% 23% 29% 7%	374
	21st to end	Day	31% 11% 39% 16% 2 1	297
November	1st to 10th	Day	14% 14% 36% 24% 10% 3	270
	11th to 20th	Day	27% 16% 30% 19% 7% 1	270
	21st to end	Day	29% 15% 35% 18% 3	270
December	1st to 10th	Day	23% 20% 36% 14% 7% 1	270
	11th to 20th	Day	22% 19% 37% 18% 4	270
	21st to end	Day	26% 22% 36% 15% 1	297
January	1st to 10th	Night	23% 15% 35% 21% 5%	950
	11th to 20th	Night	25% 16% 33% 22% 4 1	950
	21st to end	Night	24% 12% 35% 25% 4	1026
February	1st to 10th	Night	27% 9% 36% 24% 4	760
	11th to 20th	Night	21% 13% 38% 25% 3	743
	21st to end	Night	28% 12% 36% 21% 3	628
March	1st to 10th	Night	20% 12% 34% 26% 7% 1	760
	11th to 20th	Night	19% 11% 37% 26% 7%	760
	21st to end	Night	25% 11% 29% 29% 5% 1	766
April	1st to 10th	Night	19% 14% 33% 27% 7% 1	570
	11th to 20th	Night	24% 10% 33% 26% 6% 1	563
	21st to end	Night	21% 9% 31% 29% 9% 1	570
May	1st to 10th	Night	22% 7% 30% 31% 9%	570
	11th to 20th	Night	22% 4 29% 31% 13% 1	561
	21st to end	Night	14% 4 24% 39% 18% 1	617
June	1st to 10th	Night	11% 3 26% 45% 14% 1	570
	11th to 20th	Night	10% 4 26% 41% 18% 1	570
	21st to end	Night	11% 4 22% 38% 24% 1	570
July	1st to 10th	Night	7% 2 15% 43% 27% 6%	539
	11th to 20th	Night	9% 2 17% 39% 30% 3	522
	21st to end	Night	8% 1 15% 42% 33% 2	591
August	1st to 10th	Night	9% 1 11% 45% 29% 5%	537
	11th to 20th	Night	8% 1 13% 46% 27% 5%	534
	21st to end	Night	12% 1 15% 34% 33% 4	594
September	1st to 10th	Night	14% 4 14% 38% 27% 3	553
	11th to 20th	Night	12% 3 16% 35% 30% 4	720
	21st to end	Night	16% 5% 23% 32% 20% 4	720
October	1st to 10th	Night	15% 7% 24% 33% 19% 2	720
	11th to 20th	Night	23% 15% 26% 27% 7% 1	720
	21st to end	Night	28% 11% 31% 23% 7%	792
November	1st to 10th	Night	17% 13% 32% 27% 11% 1	740
	11th to 20th	Night	24% 14% 33% 24% 5% 1	760
	21st to end	Night	26% 12% 32% 26% 4	760
December	1st to 10th	Night	26% 14% 34% 21% 5%	824
	11th to 20th	Night	23% 15% 35% 22% 5%	950
	21st to end	Night	31% 14% 32% 20% 2	1045

Page generated at 2024-07-02 06:41:28. Version ac07

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