Benton Harbor
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Benton Harbor 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% 10% 4 8% 5% 4 4 3 5% 7% 36%	101213
	Night	16% 13% 5% 9% 5% 4 4 3 5% 6% 31%	97847
Transparency	Day	49% 2 11% 24% 13% 1	104797
	Night	54% 2 10% 20% 13% 1	102391
Seeing	Day	19% 11% 28% 24% 13% 4	15785
	Night	22% 9% 27% 28% 12% 1	25621

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% 24% 10% 13% 7% 4 3 3 4 5% 12%	2527
	11th to 20th	Day	13% 19% 8% 18% 11% 12% 5% 2 2 3 7%	2530
	21st to end	Day	24% 24% 7% 13% 6% 3 3 3 3 4 11%	2783
February	1st to 10th	Day	13% 17% 6% 13% 11% 5% 4 4 3 4 19%	1790
	11th to 20th	Day	13% 15% 7% 15% 8% 5% 4 3 4 5% 22%	1848
	21st to end	Day	16% 15% 6% 12% 5% 5% 5% 3 5% 5% 23%	1570
March	1st to 10th	Day	16% 13% 6% 9% 4 4 4 3 5% 6% 30%	3120
	11th to 20th	Day	11% 8% 8% 10% 5% 4 5% 4 6% 7% 32%	3335
	21st to end	Day	19% 11% 6% 11% 5% 4 4 3 5% 5% 26%	4036
April	1st to 10th	Day	17% 13% 3 7% 4 4 3 3 5% 7% 33%	2280
	11th to 20th	Day	15% 11% 3 5% 4 3 4 3 5% 7% 39%	2258
	21st to end	Day	18% 9% 3 7% 5% 4 4 3 5% 7% 36%	2470
May	1st to 10th	Day	17% 7% 2 5% 4 4 5% 4 6% 8% 37%	4082
	11th to 20th	Day	14% 8% 2 6% 4 4 4 3 5% 8% 43%	4108
	21st to end	Day	11% 6% 2 5% 4 4 4 4 5% 9% 47%	4824
June	1st to 10th	Day	9% 6% 2 5% 4 4 4 3 6% 8% 47%	2660
	11th to 20th	Day	9% 5% 2 6% 4 4 4 4 6% 8% 48%	2660
	21st to end	Day	12% 5% 2 6% 4 4 4 4 6% 8% 46%	2660
July	1st to 10th	Day	12% 7% 2 7% 4 5% 5% 4 5% 8% 41%	4440
	11th to 20th	Day	7% 3 2 4 4 3 4 4 6% 10% 53%	4440
	21st to end	Day	6% 6% 2 6% 4 4 5% 4 6% 8% 48%	4813
August	1st to 10th	Day	11% 5% 2 5% 3 4 4 3 6% 8% 48%	4174
	11th to 20th	Day	11% 5% 2 5% 3 4 4 4 5% 7% 50%	3958
	21st to end	Day	8% 5% 2 6% 5% 4 4 4 6% 8% 50%	4180
September	1st to 10th	Day	10% 5% 2 6% 4 3 5% 3 6% 7% 48%	2278
	11th to 20th	Day	12% 4 2 4 4 5% 3 3 7% 8% 48%	2090
	21st to end	Day	14% 6% 2 7% 4 4 4 4 6% 8% 40%	2090
October	1st to 10th	Day	16% 8% 3 6% 3 3 4 3 4 4 45%	2090
	11th to 20th	Day	23% 9% 3 7% 4 4 3 4 6% 7% 31%	1860
	21st to end	Day	24% 10% 3 8% 5% 5% 5% 3 5% 6% 24%	1881
November	1st to 10th	Day	15% 14% 3 6% 4 3 4 3 5% 5% 37%	1699
	11th to 20th	Day	16% 20% 5% 9% 5% 4 4 3 4 5% 23%	1710
	21st to end	Day	22% 18% 7% 10% 4 3 3 3 4 5% 22%	1710
December	1st to 10th	Day	16% 24% 10% 11% 5% 4 3 2 4 4 18%	1558
	11th to 20th	Day	14% 24% 11% 13% 5% 3 3 2 4 4 16%	1918
	21st to end	Day	22% 24% 8% 13% 6% 3 3 3 3 5% 10%	2783
January	1st to 10th	Night	17% 24% 11% 13% 6% 4 4 3 4 4 11%	4428
	11th to 20th	Night	16% 22% 10% 17% 7% 11% 3 2 3 2 9%	4440
	21st to end	Night	25% 21% 10% 13% 6% 3 4 2 3 3 10%	4884
February	1st to 10th	Night	15% 17% 5% 14% 10% 4 3 2 3 5% 20%	2384
	11th to 20th	Night	13% 17% 6% 15% 8% 5% 4 3 4 5% 21%	2218
	21st to end	Night	19% 16% 6% 12% 5% 3 4 2 3 5% 25%	1884
March	1st to 10th	Night	17% 12% 5% 9% 5% 4 4 3 4 6% 33%	3733
	11th to 20th	Night	10% 8% 4 8% 5% 6% 5% 3 5% 5% 41%	3624
	21st to end	Night	20% 11% 6% 10% 4 4 4 3 4 6% 27%	3611
April	1st to 10th	Night	16% 10% 3 7% 5% 5% 4 3 5% 6% 36%	1900
	11th to 20th	Night	21% 9% 2 7% 3 4 4 4 4 5% 37%	1870
	21st to end	Night	19% 6% 3 7% 5% 4 4 4 5% 6% 36%	1710
May	1st to 10th	Night	16% 9% 3 6% 5% 5% 4 4 6% 8% 35%	2813
	11th to 20th	Night	19% 7% 3 7% 4 3 3 3 5% 8% 39%	2782
	21st to end	Night	15% 6% 2 6% 5% 4 4 3 6% 7% 42%	2743
June	1st to 10th	Night	10% 5% 2 5% 4 4 4 4 6% 10% 48%	1520
	11th to 20th	Night	9% 6% 1 5% 5% 4 5% 5% 6% 8% 44%	1520
	21st to end	Night	9% 6% 2 7% 4 6% 5% 4 8% 9% 41%	1520
July	1st to 10th	Night	10% 5% 2 6% 5% 4 5% 4 7% 9% 41%	2530
	11th to 20th	Night	8% 4 2 4 4 3 3 4 5% 8% 55%	2530
	21st to end	Night	7% 5% 2 5% 5% 5% 5% 5% 8% 8% 47%	2750
August	1st to 10th	Night	9% 5% 2 6% 4 5% 5% 4 6% 8% 47%	2754
	11th to 20th	Night	10% 4 2 5% 4 4 4 4 6% 7% 51%	2868
	21st to end	Night	10% 5% 2 6% 4 4 5% 4 5% 7% 48%	3476
September	1st to 10th	Night	11% 5% 2 6% 4 3 4 3 5% 6% 50%	1900
	11th to 20th	Night	12% 4 2 4 3 3 4 3 6% 8% 52%	2072
	21st to end	Night	13% 7% 2 7% 4 4 5% 4 6% 7% 42%	2090
October	1st to 10th	Night	16% 7% 2 6% 4 3 3 3 5% 5% 46%	2090
	11th to 20th	Night	22% 11% 3 6% 4 4 4 3 4 6% 35%	2314
	21st to end	Night	26% 11% 3 7% 4 3 4 3 4 5% 30%	2717
November	1st to 10th	Night	16% 13% 3 7% 4 4 4 3 4 5% 37%	2452
	11th to 20th	Night	18% 20% 5% 9% 4 4 4 3 5% 5% 24%	2470
	21st to end	Night	20% 21% 6% 8% 4 4 3 2 3 5% 24%	2470
December	1st to 10th	Night	18% 26% 8% 10% 5% 3 4 2 3 4 15%	2617
	11th to 20th	Night	16% 23% 10% 14% 5% 4 3 3 4 4 14%	3279
	21st to end	Night	25% 24% 7% 11% 5% 4 4 3 3 4 11%	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	77% 1 10% 9% 2	2528
	11th to 20th	Day	86% 2 6% 6% 1	2530
	21st to end	Day	80% 1 7% 9% 2	2783
February	1st to 10th	Day	71% 2 9% 13% 5% 1	1790
	11th to 20th	Day	67% 2 9% 15% 7%	1858
	21st to end	Day	65% 2 10% 15% 7% 1	1570
March	1st to 10th	Day	58% 1 11% 21% 9%	3120
	11th to 20th	Day	52% 1 12% 26% 7% 1	3335
	21st to end	Day	62% 1 10% 21% 5% 1	4036
April	1st to 10th	Day	52% 3 9% 22% 13%	2280
	11th to 20th	Day	47% 2 9% 24% 15% 3	2258
	21st to end	Day	50% 1 11% 20% 15% 2	2470
May	1st to 10th	Day	46% 2 10% 28% 12% 1	4120
	11th to 20th	Day	42% 2 12% 29% 14% 1	4112
	21st to end	Day	36% 2 10% 26% 24% 2	4837
June	1st to 10th	Day	36% 3 11% 27% 20% 2	2660
	11th to 20th	Day	34% 3 12% 28% 21% 3	2660
	21st to end	Day	38% 3 15% 24% 17% 3	2660
July	1st to 10th	Day	44% 2 12% 23% 16% 3	4371
	11th to 20th	Day	29% 2 15% 35% 17% 2	4365
	21st to end	Day	36% 3 16% 21% 21% 3	4662
August	1st to 10th	Day	35% 2 13% 32% 15% 1	4159
	11th to 20th	Day	34% 2 13% 34% 15% 1	3997
	21st to end	Day	34% 2 12% 29% 20% 2	4179
September	1st to 10th	Day	36% 3 14% 27% 17% 4	2278
	11th to 20th	Day	35% 2 11% 32% 18% 2	2090
	21st to end	Day	42% 3 9% 27% 17% 1	2090
October	1st to 10th	Day	31% 2 8% 39% 19% 1	3480
	11th to 20th	Day	43% 1 11% 25% 20%	3063
	21st to end	Day	53% 1 9% 25% 10% 1	3081
November	1st to 10th	Day	49% 3 13% 21% 14% 1	1699
	11th to 20th	Day	64% 1 10% 18% 6% 1	1710
	21st to end	Day	66% 2 11% 17% 4	1710
December	1st to 10th	Day	73% 1 9% 13% 4	1558
	11th to 20th	Day	74% 1 11% 11% 2	1915
	21st to end	Day	80% 2 8% 9% 2	2783
January	1st to 10th	Night	79% 1 8% 9% 2	4428
	11th to 20th	Night	85% 1 6% 5% 2	4440
	21st to end	Night	83% 1 8% 7% 1	4884
February	1st to 10th	Night	69% 2 9% 13% 6% 1	2384
	11th to 20th	Night	67% 2 7% 17% 6%	2219
	21st to end	Night	65% 2 8% 17% 7% 2	1884
March	1st to 10th	Night	55% 1 12% 24% 7%	3733
	11th to 20th	Night	48% 1 11% 25% 13% 2	3624
	21st to end	Night	61% 1 11% 19% 8% 1	3611
April	1st to 10th	Night	50% 3 11% 23% 13% 1	1900
	11th to 20th	Night	51% 2 6% 20% 18% 3	1870
	21st to end	Night	50% 2 11% 20% 15% 3	1710
May	1st to 10th	Night	49% 1 11% 25% 13% 1	2840
	11th to 20th	Night	45% 2 10% 24% 17% 1	2783
	21st to end	Night	43% 2 9% 21% 23% 2	2751
June	1st to 10th	Night	33% 3 12% 30% 18% 3	1520
	11th to 20th	Night	37% 3 12% 25% 20% 2	1520
	21st to end	Night	38% 4 16% 24% 15% 2	1520
July	1st to 10th	Night	41% 2 12% 27% 13% 6%	2490
	11th to 20th	Night	29% 2 14% 25% 28% 3	2482
	21st to end	Night	35% 4 15% 18% 25% 2	2662
August	1st to 10th	Night	36% 2 13% 30% 18% 1	2745
	11th to 20th	Night	34% 3 10% 32% 20% 1	2895
	21st to end	Night	36% 2 8% 31% 20% 3	3476
September	1st to 10th	Night	36% 3 11% 27% 19% 4	1900
	11th to 20th	Night	32% 2 7% 32% 24% 2	2072
	21st to end	Night	42% 3 9% 26% 18% 2	2090
October	1st to 10th	Night	30% 1 9% 33% 26% 1	3480
	11th to 20th	Night	45% 1 8% 22% 22% 1	3837
	21st to end	Night	47% 1 8% 27% 16% 1	4467
November	1st to 10th	Night	51% 3 8% 23% 14% 2	2452
	11th to 20th	Night	63% 2 10% 17% 7% 1	2470
	21st to end	Night	65% 2 11% 17% 5%	2470
December	1st to 10th	Night	75% 1 8% 12% 4	2617
	11th to 20th	Night	76% 2 9% 11% 2	3281
	21st to end	Night	80% 1 10% 8% 2	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	22% 18% 35% 18% 6% 1	270
	11th to 20th	Day	24% 14% 39% 18% 4 1	270
	21st to end	Day	28% 14% 31% 23% 3	297
February	1st to 10th	Day	24% 22% 30% 17% 5% 1	270
	11th to 20th	Day	23% 28% 30% 16% 3	270
	21st to end	Day	26% 27% 36% 10% 2	225
March	1st to 10th	Day	21% 24% 36% 13% 4	270
	11th to 20th	Day	25% 18% 31% 19% 6% 1	367
	21st to end	Day	30% 16% 29% 19% 6% 1	506
April	1st to 10th	Day	27% 15% 33% 19% 4 1	460
	11th to 20th	Day	24% 21% 28% 18% 7% 2	452
	21st to end	Day	27% 11% 33% 17% 9% 2	460
May	1st to 10th	Day	26% 13% 30% 21% 8% 2	463
	11th to 20th	Day	20% 10% 31% 24% 11% 4	501
	21st to end	Day	15% 8% 31% 26% 14% 6%	734
June	1st to 10th	Day	12% 9% 32% 29% 13% 5%	680
	11th to 20th	Day	12% 8% 29% 31% 16% 4	680
	21st to end	Day	14% 7% 31% 29% 15% 4	680
July	1st to 10th	Day	10% 4 24% 30% 22% 10%	671
	11th to 20th	Day	11% 4 29% 32% 16% 7%	668
	21st to end	Day	8% 3 26% 36% 21% 6%	739
August	1st to 10th	Day	11% 3 19% 32% 25% 11%	531
	11th to 20th	Day	12% 4 25% 24% 27% 8%	479
	21st to end	Day	10% 4 19% 33% 24% 9%	539
September	1st to 10th	Day	15% 5% 20% 32% 20% 8%	490
	11th to 20th	Day	11% 3 18% 29% 26% 13%	490
	21st to end	Day	18% 11% 20% 24% 18% 9%	490
October	1st to 10th	Day	20% 8% 24% 29% 16% 3	490
	11th to 20th	Day	26% 13% 31% 24% 6%	357
	21st to end	Day	38% 10% 30% 18% 4	330
November	1st to 10th	Day	21% 16% 28% 25% 8% 1	279
	11th to 20th	Day	27% 20% 29% 19% 6%	270
	21st to end	Day	35% 12% 36% 14% 3	270
December	1st to 10th	Day	26% 22% 31% 14% 6%	270
	11th to 20th	Day	24% 25% 33% 14% 4 1	270
	21st to end	Day	26% 26% 31% 16% 1	297
January	1st to 10th	Night	27% 14% 32% 21% 5%	950
	11th to 20th	Night	28% 15% 32% 20% 5% 1	950
	21st to end	Night	26% 13% 32% 24% 4	1045
February	1st to 10th	Night	28% 11% 34% 23% 4	810
	11th to 20th	Night	25% 14% 32% 25% 4	743
	21st to end	Night	28% 15% 36% 18% 3	628
March	1st to 10th	Night	23% 14% 31% 25% 7% 1	760
	11th to 20th	Night	20% 12% 35% 26% 7% 1	760
	21st to end	Night	25% 8% 31% 28% 7% 1	720
April	1st to 10th	Night	21% 13% 33% 25% 7% 1	570
	11th to 20th	Night	26% 9% 30% 27% 6% 1	563
	21st to end	Night	22% 9% 32% 28% 8% 1	570
May	1st to 10th	Night	21% 5% 31% 32% 9% 1	570
	11th to 20th	Night	22% 4 24% 34% 16% 1	561
	21st to end	Night	13% 3 25% 39% 18% 2	617
June	1st to 10th	Night	13% 3 22% 42% 19% 1	570
	11th to 20th	Night	14% 2 27% 39% 17% 1	570
	21st to end	Night	12% 3 23% 37% 24% 1	570
July	1st to 10th	Night	10% 1 16% 39% 29% 5%	555
	11th to 20th	Night	11% 2 16% 39% 28% 4	552
	21st to end	Night	10% 1 14% 44% 29% 3	624
August	1st to 10th	Night	10% 1 12% 45% 30% 3	567
	11th to 20th	Night	10% 2 13% 40% 29% 5%	564
	21st to end	Night	12% 2 13% 38% 31% 4	627
September	1st to 10th	Night	14% 4 15% 38% 24% 5%	570
	11th to 20th	Night	12% 5% 15% 36% 28% 4	742
	21st to end	Night	18% 5% 23% 28% 21% 5%	760
October	1st to 10th	Night	20% 5% 22% 32% 20% 1	760
	11th to 20th	Night	30% 11% 24% 26% 8% 1	760
	21st to end	Night	34% 12% 27% 22% 6%	836
November	1st to 10th	Night	26% 12% 29% 23% 10% 1	755
	11th to 20th	Night	30% 16% 29% 22% 4	760
	21st to end	Night	33% 11% 30% 22% 4	760
December	1st to 10th	Night	30% 18% 30% 18% 4	907
	11th to 20th	Night	30% 13% 33% 21% 3	950
	21st to end	Night	34% 15% 33% 17% 2	1045

Page generated at 2024-11-01 22:47:30. Version ac07

Copyright © 2024 Attilla Danko.