Livonia
Clear Sky Chart
History

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

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% 3 8% 5% 5% 5% 4 6% 7% 33%	100887
	Night	15% 10% 4 8% 5% 4 4 4 5% 6% 35%	98124
Transparency	Day	47% 6% 12% 21% 12% 1	104515
	Night	47% 6% 11% 22% 13% 1	102636
Seeing	Day	18% 13% 30% 22% 12% 4	15427
	Night	20% 11% 29% 28% 12% 1	25269

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	16% 18% 6% 11% 6% 6% 4 4 4 5% 21%	2527
	11th to 20th	Day	16% 17% 7% 13% 7% 8% 7% 4 5% 5% 12%	2530
	21st to end	Day	27% 20% 7% 11% 7% 4 3 3 3 3 12%	3097
February	1st to 10th	Day	15% 15% 4 12% 8% 6% 5% 4 5% 5% 21%	1710
	11th to 20th	Day	14% 14% 4 12% 8% 6% 5% 3 5% 6% 23%	1794
	21st to end	Day	16% 15% 4 11% 5% 4 4 4 5% 7% 25%	1570
March	1st to 10th	Day	18% 16% 4 10% 6% 4 4 3 4 5% 26%	3204
	11th to 20th	Day	13% 12% 4 10% 6% 5% 5% 3 5% 7% 32%	3480
	21st to end	Day	19% 13% 4 9% 6% 5% 4 4 5% 5% 27%	3815
April	1st to 10th	Day	15% 13% 3 7% 5% 5% 5% 4 5% 7% 30%	2204
	11th to 20th	Day	18% 10% 3 7% 5% 4 5% 3 4 7% 35%	2409
	21st to end	Day	19% 9% 3 7% 5% 4 4 3 5% 7% 34%	2470
May	1st to 10th	Day	18% 9% 2 7% 4 5% 5% 4 5% 7% 35%	4082
	11th to 20th	Day	16% 8% 3 7% 5% 5% 4 5% 6% 8% 33%	4081
	21st to end	Day	10% 6% 2 7% 5% 5% 5% 3 5% 8% 45%	4476
June	1st to 10th	Day	10% 6% 3 7% 6% 5% 5% 4 6% 8% 40%	2637
	11th to 20th	Day	11% 5% 2 6% 4 6% 5% 4 7% 9% 40%	2816
	21st to end	Day	9% 6% 3 6% 5% 5% 6% 5% 8% 9% 37%	2660
July	1st to 10th	Day	11% 6% 2 7% 5% 5% 6% 5% 7% 9% 38%	4440
	11th to 20th	Day	7% 5% 2 5% 4 4 5% 5% 8% 11% 44%	4440
	21st to end	Day	6% 5% 2 6% 6% 5% 6% 5% 8% 10% 40%	4511
August	1st to 10th	Day	10% 6% 2 6% 4 5% 5% 5% 7% 8% 41%	4104
	11th to 20th	Day	10% 5% 3 7% 6% 5% 6% 5% 9% 9% 35%	4044
	21st to end	Day	8% 5% 2 7% 5% 6% 6% 5% 7% 10% 38%	4482
September	1st to 10th	Day	11% 6% 2 6% 5% 5% 6% 5% 7% 8% 39%	2143
	11th to 20th	Day	8% 5% 2 5% 5% 4 6% 4 6% 9% 46%	2090
	21st to end	Day	15% 7% 2 8% 5% 4 5% 4 6% 9% 36%	2090
October	1st to 10th	Day	12% 7% 3 7% 5% 4 4 4 6% 8% 41%	2038
	11th to 20th	Day	17% 9% 3 7% 5% 5% 5% 4 6% 6% 33%	1900
	21st to end	Day	19% 10% 3 8% 5% 5% 4 4 5% 7% 31%	1943
November	1st to 10th	Day	11% 9% 3 8% 5% 5% 4 4 6% 7% 39%	1708
	11th to 20th	Day	14% 12% 4 8% 6% 5% 5% 3 6% 6% 31%	1710
	21st to end	Day	19% 13% 4 8% 5% 5% 4 4 4 7% 27%	1624
December	1st to 10th	Day	15% 13% 7% 13% 7% 5% 5% 3 5% 5% 22%	1520
	11th to 20th	Day	16% 16% 5% 10% 6% 4 4 4 6% 6% 22%	1778
	21st to end	Day	27% 20% 7% 11% 5% 4 3 3 4 5% 10%	2760
January	1st to 10th	Night	17% 16% 6% 11% 6% 4 4 3 4 5% 24%	4428
	11th to 20th	Night	15% 18% 7% 13% 6% 5% 6% 5% 5% 4 15%	4440
	21st to end	Night	24% 18% 8% 11% 5% 4 3 3 3 4 17%	4556
February	1st to 10th	Night	16% 15% 4 11% 7% 4 5% 4 4 5% 24%	2470
	11th to 20th	Night	15% 13% 5% 10% 7% 5% 4 3 5% 6% 27%	2270
	21st to end	Night	19% 12% 4 9% 6% 5% 4 3 5% 6% 29%	1884
March	1st to 10th	Night	16% 14% 4 8% 5% 3 3 3 5% 6% 34%	3648
	11th to 20th	Night	10% 8% 3 6% 4 5% 5% 4 6% 8% 41%	3480
	21st to end	Night	17% 8% 3 8% 5% 5% 4 3 5% 6% 35%	3817
April	1st to 10th	Night	15% 10% 4 6% 5% 4 4 3 5% 7% 36%	1991
	11th to 20th	Night	18% 8% 3 6% 4 4 4 4 7% 6% 37%	1720
	21st to end	Night	17% 8% 3 6% 5% 4 5% 4 4 6% 38%	1710
May	1st to 10th	Night	18% 8% 3 7% 5% 4 4 3 5% 7% 36%	2813
	11th to 20th	Night	15% 7% 3 7% 4 4 5% 3 5% 7% 40%	2812
	21st to end	Night	10% 6% 2 6% 4 4 4 3 6% 8% 48%	3079
June	1st to 10th	Night	12% 6% 2 4 3 4 4 3 6% 10% 46%	1521
	11th to 20th	Night	9% 4 2 7% 4 5% 5% 4 6% 8% 45%	1345
	21st to end	Night	10% 4 2 6% 4 4 3 4 6% 8% 48%	1520
July	1st to 10th	Night	8% 4 2 5% 3 4 5% 5% 7% 11% 48%	2530
	11th to 20th	Night	8% 4 2 4 4 4 4 4 6% 9% 53%	2530
	21st to end	Night	5% 4 2 6% 5% 5% 6% 5% 7% 9% 47%	3042
August	1st to 10th	Night	11% 7% 2 6% 4 4 4 3 6% 8% 46%	2825
	11th to 20th	Night	7% 7% 2 6% 4 5% 4 3 5% 8% 49%	2785
	21st to end	Night	8% 5% 2 6% 4 5% 5% 3 6% 8% 48%	3171
September	1st to 10th	Night	10% 5% 2 5% 4 5% 4 4 6% 7% 48%	2017
	11th to 20th	Night	8% 5% 1 4 3 3 4 4 5% 7% 55%	2090
	21st to end	Night	15% 7% 2 6% 4 3 4 4 5% 7% 43%	2090
October	1st to 10th	Night	13% 7% 3 6% 3 4 3 3 5% 7% 46%	2142
	11th to 20th	Night	18% 8% 3 7% 4 5% 5% 4 5% 5% 36%	2280
	21st to end	Night	20% 9% 3 8% 4 4 4 4 5% 6% 34%	2652
November	1st to 10th	Night	13% 7% 3 6% 4 5% 4 4 5% 6% 43%	2470
	11th to 20th	Night	16% 11% 4 7% 5% 4 5% 4 6% 7% 31%	2470
	21st to end	Night	20% 14% 4 7% 4 4 4 3 5% 6% 30%	2550
December	1st to 10th	Night	17% 16% 5% 10% 6% 5% 5% 4 5% 5% 21%	2660
	11th to 20th	Night	15% 15% 5% 10% 6% 5% 5% 3 6% 6% 24%	3414
	21st to end	Night	28% 22% 6% 10% 4 3 3 3 4 4 12%	4902

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	63% 7% 11% 12% 6%	2528
	11th to 20th	Day	73% 6% 9% 7% 4	2530
	21st to end	Day	78% 4 8% 6% 3 1	3097
February	1st to 10th	Day	63% 6% 9% 14% 7%	1710
	11th to 20th	Day	62% 5% 8% 16% 7% 1	1804
	21st to end	Day	59% 5% 11% 16% 7% 1	1570
March	1st to 10th	Day	60% 5% 11% 19% 5% 1	3204
	11th to 20th	Day	51% 5% 14% 20% 8% 2	3480
	21st to end	Day	57% 6% 12% 15% 9% 1	3815
April	1st to 10th	Day	52% 6% 11% 19% 12% 1	2204
	11th to 20th	Day	49% 5% 11% 20% 13% 2	2409
	21st to end	Day	50% 5% 12% 17% 14% 1	2470
May	1st to 10th	Day	48% 7% 10% 23% 11% 2	4120
	11th to 20th	Day	46% 9% 12% 23% 9% 1	4085
	21st to end	Day	36% 6% 11% 19% 22% 6%	4489
June	1st to 10th	Day	40% 7% 11% 26% 14% 3	2637
	11th to 20th	Day	39% 7% 12% 23% 17% 3	2816
	21st to end	Day	39% 8% 13% 21% 17% 2	2660
July	1st to 10th	Day	41% 6% 13% 21% 17% 2	4371
	11th to 20th	Day	31% 6% 13% 31% 17% 1	4365
	21st to end	Day	36% 8% 14% 18% 22% 2	4368
August	1st to 10th	Day	37% 7% 13% 27% 15% 1	4091
	11th to 20th	Day	40% 8% 10% 29% 12% 1	4083
	21st to end	Day	38% 8% 13% 27% 13% 1	4481
September	1st to 10th	Day	40% 8% 13% 22% 14% 2	2143
	11th to 20th	Day	32% 8% 12% 32% 16% 1	2090
	21st to end	Day	43% 7% 13% 24% 13%	2090
October	1st to 10th	Day	31% 5% 12% 31% 21% 1	3389
	11th to 20th	Day	39% 4 11% 27% 18%	3140
	21st to end	Day	44% 5% 13% 24% 13% 1	3180
November	1st to 10th	Day	44% 7% 12% 23% 13% 1	1708
	11th to 20th	Day	52% 5% 13% 19% 9% 1	1710
	21st to end	Day	56% 6% 12% 19% 7% 1	1624
December	1st to 10th	Day	64% 6% 12% 13% 5%	1520
	11th to 20th	Day	61% 6% 13% 15% 5%	1774
	21st to end	Day	78% 4 9% 6% 3	2760
January	1st to 10th	Night	61% 6% 12% 15% 6% 1	4428
	11th to 20th	Night	70% 6% 10% 9% 4	4440
	21st to end	Night	72% 5% 9% 11% 3	4556
February	1st to 10th	Night	62% 6% 11% 14% 6% 1	2470
	11th to 20th	Night	58% 5% 10% 18% 9% 1	2271
	21st to end	Night	56% 5% 12% 18% 8% 1	1884
March	1st to 10th	Night	51% 5% 12% 24% 7%	3648
	11th to 20th	Night	38% 7% 15% 20% 19% 1	3480
	21st to end	Night	48% 6% 11% 23% 11% 1	3817
April	1st to 10th	Night	48% 6% 10% 21% 14% 2	1991
	11th to 20th	Night	45% 6% 10% 19% 18% 2	1720
	21st to end	Night	46% 5% 10% 19% 16% 3	1710
May	1st to 10th	Night	47% 7% 8% 22% 14% 2	2840
	11th to 20th	Night	43% 8% 9% 27% 12% 2	2813
	21st to end	Night	33% 7% 11% 21% 22% 5%	3087
June	1st to 10th	Night	35% 6% 11% 27% 17% 3	1521
	11th to 20th	Night	36% 7% 12% 26% 17% 2	1345
	21st to end	Night	33% 8% 11% 26% 21% 1	1520
July	1st to 10th	Night	29% 7% 12% 32% 14% 6%	2490
	11th to 20th	Night	27% 7% 14% 32% 19% 1	2482
	21st to end	Night	31% 8% 18% 19% 21% 3	2945
August	1st to 10th	Night	36% 7% 12% 28% 17% 1	2814
	11th to 20th	Night	34% 7% 10% 36% 12% 2	2812
	21st to end	Night	34% 7% 11% 32% 15% 1	3171
September	1st to 10th	Night	33% 8% 12% 27% 18% 2	2017
	11th to 20th	Night	29% 6% 10% 32% 21% 2	2090
	21st to end	Night	41% 6% 11% 28% 14% 1	2090
October	1st to 10th	Night	26% 4 9% 33% 28% 1	3571
	11th to 20th	Night	42% 4 11% 24% 19%	3779
	21st to end	Night	40% 4 11% 30% 14% 1	4365
November	1st to 10th	Night	42% 5% 12% 26% 15% 1	2470
	11th to 20th	Night	50% 5% 13% 21% 9% 1	2470
	21st to end	Night	56% 5% 13% 20% 7%	2550
December	1st to 10th	Night	64% 6% 10% 14% 6%	2660
	11th to 20th	Night	60% 6% 14% 13% 6% 1	3417
	21st to end	Night	76% 5% 10% 7% 2	4902

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	26% 21% 32% 15% 6%	270
	11th to 20th	Day	25% 18% 39% 15% 2 1	270
	21st to end	Day	28% 15% 35% 16% 4 1	297
February	1st to 10th	Day	24% 21% 37% 15% 3 1	270
	11th to 20th	Day	26% 18% 38% 16% 2	270
	21st to end	Day	25% 31% 33% 8% 2	225
March	1st to 10th	Day	29% 21% 30% 16% 4	315
	11th to 20th	Day	24% 14% 35% 20% 6% 1	460
	21st to end	Day	27% 17% 33% 17% 5% 1	506
April	1st to 10th	Day	21% 18% 33% 20% 7% 1	460
	11th to 20th	Day	26% 20% 29% 14% 8% 3	452
	21st to end	Day	26% 18% 29% 17% 8% 3	460
May	1st to 10th	Day	24% 16% 29% 20% 8% 4	463
	11th to 20th	Day	20% 11% 32% 21% 12% 5%	487
	21st to end	Day	13% 9% 25% 28% 18% 7%	529
June	1st to 10th	Day	12% 11% 33% 29% 13% 3	651
	11th to 20th	Day	14% 9% 32% 30% 13% 3	680
	21st to end	Day	12% 11% 33% 26% 14% 4	680
July	1st to 10th	Day	9% 6% 27% 28% 21% 8%	671
	11th to 20th	Day	9% 9% 30% 28% 17% 7%	668
	21st to end	Day	9% 5% 28% 27% 22% 9%	564
August	1st to 10th	Day	9% 4 27% 28% 20% 12%	486
	11th to 20th	Day	13% 5% 24% 29% 18% 11%	479
	21st to end	Day	10% 6% 22% 29% 23% 9%	539
September	1st to 10th	Day	12% 7% 25% 25% 21% 10%	490
	11th to 20th	Day	9% 5% 21% 27% 27% 12%	490
	21st to end	Day	17% 11% 25% 22% 17% 7%	490
October	1st to 10th	Day	15% 12% 27% 22% 17% 7%	490
	11th to 20th	Day	20% 18% 29% 23% 8% 2	490
	21st to end	Day	29% 16% 35% 15% 5% 1	392
November	1st to 10th	Day	15% 23% 35% 18% 9% 1	282
	11th to 20th	Day	23% 24% 29% 17% 6% 1	270
	21st to end	Day	28% 19% 35% 13% 6%	229
December	1st to 10th	Day	24% 22% 34% 14% 6% 1	180
	11th to 20th	Day	27% 24% 36% 9% 3 1	180
	21st to end	Day	30% 24% 31% 12% 2	292
January	1st to 10th	Night	23% 17% 34% 20% 5% 1	950
	11th to 20th	Night	28% 14% 32% 22% 5% 1	950
	21st to end	Night	22% 14% 33% 26% 5%	847
February	1st to 10th	Night	26% 13% 35% 23% 3	760
	11th to 20th	Night	24% 15% 32% 26% 4	743
	21st to end	Night	26% 16% 36% 20% 2	628
March	1st to 10th	Night	21% 13% 33% 27% 6%	760
	11th to 20th	Night	19% 17% 35% 24% 4 1	760
	21st to end	Night	24% 12% 29% 27% 7% 1	836
April	1st to 10th	Night	20% 15% 33% 27% 4	661
	11th to 20th	Night	22% 12% 34% 25% 7% 1	563
	21st to end	Night	20% 11% 31% 30% 8%	570
May	1st to 10th	Night	21% 10% 29% 31% 9% 1	570
	11th to 20th	Night	21% 6% 27% 34% 12% 1	561
	21st to end	Night	11% 5% 26% 38% 19% 2	617
June	1st to 10th	Night	13% 4 28% 41% 14%	546
	11th to 20th	Night	10% 6% 28% 45% 12%	395
	21st to end	Night	11% 5% 26% 38% 19% 1	570
July	1st to 10th	Night	9% 2 22% 39% 25% 4	555
	11th to 20th	Night	9% 4 23% 39% 21% 4	552
	21st to end	Night	5% 3 20% 47% 22% 2	624
August	1st to 10th	Night	8% 4 19% 39% 26% 3	567
	11th to 20th	Night	11% 2 20% 35% 30% 3	564
	21st to end	Night	11% 3 18% 37% 29% 3	627
September	1st to 10th	Night	14% 7% 17% 33% 25% 4	687
	11th to 20th	Night	10% 4 18% 34% 30% 3	760
	21st to end	Night	17% 7% 23% 29% 21% 4	760
October	1st to 10th	Night	17% 9% 26% 29% 17% 3	760
	11th to 20th	Night	23% 14% 27% 24% 10% 1	760
	21st to end	Night	25% 13% 30% 26% 6%	836
November	1st to 10th	Night	18% 13% 29% 27% 11% 1	760
	11th to 20th	Night	23% 16% 32% 21% 7% 1	760
	21st to end	Night	28% 13% 33% 20% 6%	760
December	1st to 10th	Night	26% 15% 34% 18% 7%	760
	11th to 20th	Night	25% 15% 36% 20% 4	845
	21st to end	Night	33% 12% 32% 20% 3	1045

Page generated at 2024-11-03 02:11:07. Version ac07

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