New Liskeard
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the New Liskeard clear sky chart from 2005-11-06 to 2026-05-02.

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	15% 11% 4 10% 6% 5% 5% 4 5% 6% 29%	131809
	Night	15% 13% 5% 11% 6% 5% 5% 4 5% 6% 26%	130789
Transparency	Day	54% 6% 12% 19% 8% 1	135297
	Night	59% 6% 11% 16% 8% 1	135389
Seeing	Day	21% 14% 30% 23% 10% 3	17016
	Night	23% 11% 30% 27% 9% 1	26170

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	12% 20% 7% 16% 9% 7% 5% 3 4 4 12%	4094
	11th to 20th	Day	9% 19% 7% 18% 8% 6% 6% 3 5% 5% 13%	4083
	21st to end	Day	7% 13% 7% 16% 9% 7% 6% 5% 6% 5% 20%	5634
February	1st to 10th	Day	7% 15% 6% 15% 9% 8% 6% 5% 5% 6% 19%	1890
	11th to 20th	Day	9% 17% 5% 12% 9% 6% 6% 4 6% 5% 20%	1843
	21st to end	Day	12% 17% 4 11% 8% 6% 5% 4 4 5% 24%	1557
March	1st to 10th	Day	18% 15% 5% 11% 5% 4 4 4 5% 6% 25%	4959
	11th to 20th	Day	15% 14% 5% 14% 7% 4 5% 3 4 5% 24%	5090
	21st to end	Day	14% 14% 6% 12% 6% 5% 5% 3 4 4 28%	5586
April	1st to 10th	Day	18% 14% 4 10% 6% 4 5% 3 5% 6% 25%	2502
	11th to 20th	Day	20% 12% 3 9% 5% 4 4 3 4 5% 31%	2676
	21st to end	Day	21% 12% 4 8% 4 4 3 3 5% 5% 32%	2730
May	1st to 10th	Day	18% 11% 3 7% 4 4 4 3 5% 6% 36%	6177
	11th to 20th	Day	13% 8% 3 8% 5% 5% 5% 4 5% 6% 39%	6318
	21st to end	Day	19% 10% 3 6% 4 4 4 3 5% 7% 36%	7077
June	1st to 10th	Day	18% 9% 2 7% 6% 5% 5% 4 6% 8% 30%	3000
	11th to 20th	Day	13% 7% 2 6% 5% 5% 5% 5% 7% 8% 36%	3000
	21st to end	Day	17% 8% 3 8% 6% 6% 5% 4 6% 7% 31%	3000
July	1st to 10th	Day	15% 6% 2 6% 5% 5% 5% 5% 7% 10% 33%	6819
	11th to 20th	Day	14% 5% 2 6% 5% 5% 5% 5% 6% 9% 39%	6820
	21st to end	Day	12% 6% 2 6% 5% 5% 5% 4 7% 10% 39%	7069
August	1st to 10th	Day	12% 6% 2 8% 5% 5% 6% 5% 7% 8% 36%	4236
	11th to 20th	Day	18% 6% 2 6% 4 4 5% 4 6% 7% 38%	4174
	21st to end	Day	12% 6% 2 7% 5% 4 5% 4 5% 8% 41%	4609
September	1st to 10th	Day	16% 7% 3 7% 5% 5% 5% 4 5% 7% 36%	2400
	11th to 20th	Day	17% 8% 2 7% 4 4 4 3 5% 7% 38%	2295
	21st to end	Day	20% 9% 3 8% 5% 5% 5% 3 4 6% 34%	2155
October	1st to 10th	Day	18% 10% 4 7% 5% 5% 5% 4 5% 6% 32%	2000
	11th to 20th	Day	22% 16% 4 8% 6% 5% 4 4 4 4 24%	2000
	21st to end	Day	24% 17% 5% 10% 5% 5% 4 4 4 5% 17%	2103
November	1st to 10th	Day	19% 15% 5% 11% 6% 3 5% 3 4 5% 24%	1646
	11th to 20th	Day	17% 15% 6% 15% 7% 5% 5% 4 5% 5% 17%	1680
	21st to end	Day	21% 21% 6% 13% 7% 6% 5% 3 3 4 10%	1680
December	1st to 10th	Day	12% 25% 9% 16% 7% 5% 5% 3 4 3 11%	2663
	11th to 20th	Day	14% 17% 6% 13% 9% 5% 4 3 4 4 21%	2691
	21st to end	Day	18% 19% 6% 17% 7% 5% 4 5% 4 4 11%	3553
January	1st to 10th	Night	9% 18% 8% 18% 10% 6% 5% 4 4 4 13%	8831
	11th to 20th	Night	9% 19% 7% 16% 8% 6% 6% 4 5% 5% 15%	8832
	21st to end	Night	7% 12% 7% 15% 9% 8% 7% 4 7% 6% 18%	8546
February	1st to 10th	Night	10% 15% 5% 12% 10% 7% 6% 5% 6% 6% 19%	2730
	11th to 20th	Night	11% 17% 6% 12% 9% 6% 5% 3 4 4 23%	2663
	21st to end	Night	11% 14% 6% 13% 8% 6% 6% 4 5% 6% 23%	2249
March	1st to 10th	Night	16% 17% 5% 10% 5% 4 5% 4 4 4 27%	5083
	11th to 20th	Night	15% 18% 5% 12% 7% 5% 4 3 4 5% 20%	5089
	21st to end	Night	16% 13% 5% 11% 5% 5% 4 3 4 5% 29%	5588
April	1st to 10th	Night	19% 16% 4 9% 4 3 3 3 5% 4 28%	2117
	11th to 20th	Night	18% 11% 4 8% 4 4 4 4 5% 5% 32%	1911
	21st to end	Night	18% 10% 3 8% 5% 4 4 3 5% 6% 34%	1890
May	1st to 10th	Night	16% 11% 4 8% 4 5% 4 3 5% 5% 35%	3786
	11th to 20th	Night	15% 6% 2 6% 4 4 4 3 5% 7% 42%	3575
	21st to end	Night	18% 8% 2 7% 4 5% 4 3 5% 7% 36%	3801
June	1st to 10th	Night	17% 8% 3 7% 5% 4 6% 5% 6% 6% 33%	1400
	11th to 20th	Night	18% 6% 2 5% 4 4 4 4 5% 8% 43%	1400
	21st to end	Night	15% 6% 3 7% 5% 5% 5% 3 6% 9% 36%	1400
July	1st to 10th	Night	16% 7% 3 7% 4 5% 5% 4 5% 7% 38%	3160
	11th to 20th	Night	15% 4 2 6% 5% 5% 5% 4 6% 7% 41%	3160
	21st to end	Night	13% 5% 2 5% 4 4 4 4 6% 8% 46%	3786
August	1st to 10th	Night	9% 5% 2 8% 6% 5% 5% 4 6% 9% 41%	2910
	11th to 20th	Night	15% 6% 3 6% 4 4 4 5% 5% 8% 40%	2875
	21st to end	Night	14% 6% 2 7% 3 4 4 3 5% 6% 44%	3256
September	1st to 10th	Night	16% 5% 2 6% 4 5% 5% 3 6% 7% 41%	2000
	11th to 20th	Night	16% 7% 2 6% 4 4 3 2 5% 6% 45%	2100
	21st to end	Night	20% 7% 2 7% 3 3 3 3 5% 7% 40%	2245
October	1st to 10th	Night	19% 11% 3 7% 4 4 4 3 5% 7% 33%	2400
	11th to 20th	Night	23% 14% 3 8% 5% 5% 5% 4 5% 5% 23%	2400
	21st to end	Night	21% 15% 4 10% 5% 5% 4 3 5% 5% 23%	2731
November	1st to 10th	Night	17% 15% 4 8% 6% 5% 5% 3 5% 6% 26%	2872
	11th to 20th	Night	17% 17% 5% 13% 7% 5% 5% 3 4 5% 19%	2940
	21st to end	Night	20% 20% 6% 11% 6% 4 5% 4 5% 5% 14%	2940
December	1st to 10th	Night	13% 22% 9% 16% 8% 5% 5% 3 3 4 10%	4720
	11th to 20th	Night	14% 17% 6% 13% 9% 6% 5% 4 4 4 18%	5736
	21st to end	Night	20% 19% 6% 15% 6% 5% 4 3 3 4 16%	7667

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	76% 5% 8% 8% 2	4095
	11th to 20th	Day	72% 5% 6% 10% 7%	4110
	21st to end	Day	63% 5% 9% 15% 8%	5634
February	1st to 10th	Day	65% 7% 9% 13% 7%	1890
	11th to 20th	Day	63% 6% 10% 13% 8%	1852
	21st to end	Day	62% 6% 8% 17% 7%	1557
March	1st to 10th	Day	61% 5% 8% 13% 11% 1	4962
	11th to 20th	Day	62% 6% 11% 13% 8% 1	5090
	21st to end	Day	60% 4 8% 19% 8% 1	5586
April	1st to 10th	Day	58% 5% 11% 17% 8% 1	2502
	11th to 20th	Day	54% 6% 8% 21% 10% 1	2676
	21st to end	Day	53% 6% 8% 17% 14% 2	2730
May	1st to 10th	Day	48% 6% 10% 18% 15% 3	6186
	11th to 20th	Day	43% 9% 14% 19% 12% 2	6322
	21st to end	Day	48% 6% 11% 19% 14% 1	7077
June	1st to 10th	Day	50% 8% 12% 20% 9% 1	3000
	11th to 20th	Day	43% 7% 13% 23% 12% 1	3000
	21st to end	Day	51% 8% 12% 20% 9% 1	3000
July	1st to 10th	Day	44% 7% 17% 26% 5%	6746
	11th to 20th	Day	40% 7% 19% 28% 6%	6739
	21st to end	Day	39% 7% 16% 31% 7%	6868
August	1st to 10th	Day	43% 8% 17% 26% 6%	4222
	11th to 20th	Day	43% 8% 15% 24% 8% 1	4213
	21st to end	Day	42% 7% 13% 29% 8% 2	4609
September	1st to 10th	Day	47% 8% 15% 21% 8%	2400
	11th to 20th	Day	45% 8% 16% 25% 6%	2295
	21st to end	Day	52% 7% 13% 21% 7%	2155
October	1st to 10th	Day	54% 5% 11% 24% 5%	3260
	11th to 20th	Day	58% 6% 11% 18% 8%	3240
	21st to end	Day	66% 6% 14% 9% 5%	3368
November	1st to 10th	Day	63% 6% 13% 13% 5%	1646
	11th to 20th	Day	71% 6% 8% 10% 4	1680
	21st to end	Day	81% 4 7% 6% 2	1680
December	1st to 10th	Day	81% 4 7% 5% 2	2663
	11th to 20th	Day	69% 4 9% 16% 2	2691
	21st to end	Day	77% 4 7% 9% 3	3553
January	1st to 10th	Night	74% 5% 9% 9% 3	8831
	11th to 20th	Night	71% 5% 8% 9% 7%	8880
	21st to end	Night	65% 5% 7% 15% 8%	8546
February	1st to 10th	Night	64% 6% 10% 13% 7%	2730
	11th to 20th	Night	65% 5% 11% 14% 5%	2665
	21st to end	Night	63% 6% 9% 14% 7% 1	2249
March	1st to 10th	Night	62% 4 9% 12% 9% 3	5093
	11th to 20th	Night	65% 5% 11% 12% 6% 1	5090
	21st to end	Night	58% 4 8% 16% 11% 3	5588
April	1st to 10th	Night	59% 4 10% 15% 11% 1	2117
	11th to 20th	Night	51% 5% 9% 19% 14% 2	1911
	21st to end	Night	51% 5% 10% 16% 16% 2	1890
May	1st to 10th	Night	49% 7% 7% 19% 16% 2	3793
	11th to 20th	Night	41% 6% 14% 21% 16% 2	3576
	21st to end	Night	47% 6% 11% 19% 15% 2	3802
June	1st to 10th	Night	48% 8% 11% 21% 10% 2	1400
	11th to 20th	Night	39% 9% 11% 23% 15% 3	1400
	21st to end	Night	45% 7% 13% 21% 13% 1	1400
July	1st to 10th	Night	46% 6% 13% 26% 9%	3125
	11th to 20th	Night	42% 6% 16% 28% 9%	3118
	21st to end	Night	37% 6% 16% 29% 12%	3673
August	1st to 10th	Night	39% 7% 16% 29% 9%	2900
	11th to 20th	Night	42% 7% 17% 28% 6%	2902
	21st to end	Night	42% 7% 15% 25% 10% 2	3256
September	1st to 10th	Night	41% 8% 18% 23% 9% 2	2000
	11th to 20th	Night	42% 6% 17% 26% 8%	2100
	21st to end	Night	43% 9% 15% 25% 8%	2245
October	1st to 10th	Night	50% 6% 12% 22% 10%	3920
	11th to 20th	Night	58% 5% 13% 20% 4	3899
	21st to end	Night	59% 7% 16% 12% 5%	4416
November	1st to 10th	Night	60% 7% 13% 15% 4	2872
	11th to 20th	Night	69% 7% 10% 10% 4	2940
	21st to end	Night	75% 7% 10% 7% 1	2940
December	1st to 10th	Night	80% 4 6% 7% 2	4720
	11th to 20th	Night	70% 5% 9% 11% 6%	5735
	21st to end	Night	75% 4 6% 12% 3	7667

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% 15% 38% 20% 5%	220
	11th to 20th	Day	19% 17% 32% 21% 8% 3	220
	21st to end	Day	17% 11% 36% 24% 11% 1	352
February	1st to 10th	Day	19% 23% 32% 19% 6% 1	330
	11th to 20th	Day	19% 20% 38% 18% 4	330
	21st to end	Day	26% 25% 29% 15% 5%	273
March	1st to 10th	Day	20% 17% 37% 19% 7%	503
	11th to 20th	Day	20% 19% 33% 21% 6% 1	540
	21st to end	Day	24% 16% 34% 18% 7% 1	594
April	1st to 10th	Day	23% 16% 32% 19% 8% 1	540
	11th to 20th	Day	28% 17% 24% 21% 7% 4	532
	21st to end	Day	27% 17% 26% 18% 9% 2	540
May	1st to 10th	Day	25% 11% 30% 22% 11% 2	507
	11th to 20th	Day	21% 12% 30% 23% 10% 4	527
	21st to end	Day	20% 15% 30% 24% 10% 2	623
June	1st to 10th	Day	18% 12% 34% 26% 7% 2	730
	11th to 20th	Day	17% 14% 28% 27% 12% 2	730
	21st to end	Day	19% 10% 28% 28% 12% 2	730
July	1st to 10th	Day	14% 11% 31% 28% 13% 3	721
	11th to 20th	Day	15% 10% 30% 26% 16% 3	718
	21st to end	Day	12% 10% 27% 32% 15% 4	641
August	1st to 10th	Day	15% 8% 28% 27% 17% 5%	526
	11th to 20th	Day	15% 7% 22% 29% 17% 10%	519
	21st to end	Day	17% 11% 27% 24% 13% 8%	583
September	1st to 10th	Day	20% 9% 27% 26% 13% 4	530
	11th to 20th	Day	17% 8% 23% 31% 14% 7%	530
	21st to end	Day	23% 11% 27% 20% 16% 3	530
October	1st to 10th	Day	25% 13% 27% 21% 11% 2	530
	11th to 20th	Day	28% 19% 33% 14% 5% 1	530
	21st to end	Day	32% 16% 31% 16% 4 1	495
November	1st to 10th	Day	32% 20% 35% 11% 3	220
	11th to 20th	Day	29% 16% 34% 16% 4 1	220
	21st to end	Day	34% 19% 32% 10% 4 1	220
December	1st to 10th	Day	23% 16% 35% 20% 6%	220
	11th to 20th	Day	28% 15% 34% 17% 6% 1	220
	21st to end	Day	25% 17% 32% 19% 6% 1	242
January	1st to 10th	Night	24% 13% 32% 24% 6%	1050
	11th to 20th	Night	25% 13% 31% 25% 7%	1050
	21st to end	Night	17% 9% 31% 31% 11% 1	957
February	1st to 10th	Night	16% 14% 35% 26% 8%	840
	11th to 20th	Night	20% 11% 38% 25% 5%	823
	21st to end	Night	20% 15% 34% 25% 6% 1	692
March	1st to 10th	Night	21% 15% 35% 23% 5% 1	840
	11th to 20th	Night	22% 15% 34% 23% 5%	840
	21st to end	Night	21% 12% 34% 26% 5% 1	924
April	1st to 10th	Night	26% 13% 29% 26% 5% 1	840
	11th to 20th	Night	24% 13% 28% 26% 9% 1	667
	21st to end	Night	22% 13% 29% 29% 6% 1	630
May	1st to 10th	Night	19% 9% 29% 34% 8%	483
	11th to 20th	Night	20% 8% 31% 31% 9% 1	394
	21st to end	Night	21% 7% 28% 36% 7%	433
June	1st to 10th	Night	17% 10% 31% 37% 6%	400
	11th to 20th	Night	20% 8% 27% 34% 11%	400
	21st to end	Night	17% 6% 29% 35% 14% 1	400
July	1st to 10th	Night	13% 4 33% 38% 10% 1	390
	11th to 20th	Night	16% 6% 25% 40% 13%	388
	21st to end	Night	13% 5% 26% 41% 14% 1	438
August	1st to 10th	Night	14% 5% 25% 36% 18% 2	592
	11th to 20th	Night	16% 5% 22% 34% 20% 2	594
	21st to end	Night	19% 8% 26% 29% 16% 2	680
September	1st to 10th	Night	19% 7% 29% 30% 15% 1	800
	11th to 20th	Night	20% 8% 26% 27% 18% 2	800
	21st to end	Night	23% 8% 22% 30% 15% 2	800
October	1st to 10th	Night	26% 8% 32% 25% 9% 1	800
	11th to 20th	Night	32% 12% 29% 20% 7% 1	800
	21st to end	Night	31% 11% 30% 22% 5% 1	880
November	1st to 10th	Night	27% 14% 34% 19% 6%	820
	11th to 20th	Night	25% 16% 33% 19% 6%	840
	21st to end	Night	33% 14% 29% 19% 4	840
December	1st to 10th	Night	28% 14% 32% 18% 7% 1	840
	11th to 20th	Night	26% 14% 32% 22% 5% 1	1050
	21st to end	Night	28% 15% 26% 23% 6% 1	1155

Page generated at 2026-04-29 02:21:44. Version ac07

Copyright © 2026 Attilla Danko.