Amqui
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Amqui clear sky chart from 2005-11-06 to 2026-09-29.

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	16% 11% 4 10% 6% 6% 5% 4 5% 6% 26%	150084
	Night	14% 12% 4 10% 7% 6% 6% 4 5% 6% 25%	141569
Transparency	Day	59% 4 12% 18% 7%	153508
	Night	61% 4 11% 16% 7%	146209
Seeing	Day	25% 14% 27% 21% 10% 3	18653
	Night	23% 11% 26% 28% 10% 1	26339

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	11% 19% 7% 16% 10% 10% 10% 3 4 3 6%	4093
	11th to 20th	Day	10% 13% 7% 19% 15% 10% 5% 4 4 5% 8%	4311
	21st to end	Day	3 5% 4 16% 9% 11% 10% 12% 9% 6% 14%	5124
February	1st to 10th	Day	7% 13% 4 10% 11% 10% 10% 6% 7% 5% 19%	1838
	11th to 20th	Day	9% 16% 7% 14% 9% 8% 7% 6% 4 3 17%	1843
	21st to end	Day	8% 13% 5% 13% 9% 9% 7% 3 5% 8% 21%	1679
March	1st to 10th	Day	15% 14% 5% 12% 8% 6% 8% 4 5% 6% 16%	4687
	11th to 20th	Day	16% 17% 5% 9% 6% 7% 7% 5% 6% 6% 16%	5090
	21st to end	Day	18% 17% 6% 11% 7% 6% 3 3 4 4 21%	5587
April	1st to 10th	Day	17% 14% 5% 10% 6% 6% 5% 4 4 6% 24%	2546
	11th to 20th	Day	15% 14% 3 9% 6% 4 4 4 5% 6% 30%	2702
	21st to end	Day	20% 13% 4 10% 5% 4 3 3 4 5% 28%	2730
May	1st to 10th	Day	23% 14% 4 9% 5% 4 4 4 4 5% 25%	7674
	11th to 20th	Day	20% 9% 3 9% 5% 5% 5% 4 5% 6% 29%	8531
	21st to end	Day	22% 10% 3 8% 5% 5% 4 3 4 6% 29%	9716
June	1st to 10th	Day	22% 10% 3 7% 6% 5% 4 3 4 6% 31%	3150
	11th to 20th	Day	21% 7% 2 6% 5% 4 5% 4 6% 7% 32%	3150
	21st to end	Day	21% 9% 4 8% 5% 6% 5% 4 6% 7% 25%	3150
July	1st to 10th	Day	12% 7% 3 8% 6% 5% 6% 4 7% 9% 33%	8880
	11th to 20th	Day	14% 7% 3 8% 5% 6% 6% 5% 7% 8% 31%	8880
	21st to end	Day	11% 6% 2 7% 5% 6% 6% 5% 7% 9% 36%	9272
August	1st to 10th	Day	15% 8% 3 8% 5% 5% 5% 5% 6% 8% 34%	6116
	11th to 20th	Day	16% 8% 3 9% 6% 5% 6% 5% 6% 8% 28%	5953
	21st to end	Day	15% 6% 3 7% 5% 5% 5% 4 6% 8% 36%	6594
September	1st to 10th	Day	17% 7% 3 8% 5% 4 4 3 5% 7% 36%	2550
	11th to 20th	Day	17% 7% 2 6% 4 4 4 3 4 6% 43%	2310
	21st to end	Day	16% 9% 3 7% 4 5% 4 3 5% 7% 36%	2288
October	1st to 10th	Day	16% 10% 3 8% 6% 4 3 4 5% 6% 34%	2059
	11th to 20th	Day	21% 12% 4 9% 4 5% 4 4 6% 6% 26%	1978
	21st to end	Day	22% 17% 5% 8% 5% 4 4 4 5% 6% 22%	1980
November	1st to 10th	Day	16% 17% 6% 10% 6% 6% 5% 4 5% 5% 21%	1735
	11th to 20th	Day	17% 16% 7% 15% 6% 5% 4 2 4 5% 18%	1680
	21st to end	Day	18% 17% 5% 16% 11% 5% 4 4 4 4 13%	1617
December	1st to 10th	Day	13% 15% 5% 17% 15% 7% 5% 3 4 4 13%	2350
	11th to 20th	Day	16% 14% 5% 16% 11% 6% 5% 4 4 4 15%	2688
	21st to end	Day	12% 16% 5% 16% 10% 9% 6% 3 4 5% 16%	3553
January	1st to 10th	Night	10% 18% 7% 16% 10% 10% 9% 4 4 4 7%	8831
	11th to 20th	Night	9% 16% 6% 16% 13% 9% 6% 4 5% 4 11%	8576
	21st to end	Night	3 8% 5% 13% 9% 9% 12% 12% 7% 6% 17%	9057
February	1st to 10th	Night	7% 13% 6% 11% 9% 10% 8% 5% 7% 6% 20%	2781
	11th to 20th	Night	11% 15% 5% 12% 7% 8% 7% 5% 6% 5% 20%	2663
	21st to end	Night	9% 13% 5% 10% 7% 10% 6% 4 5% 6% 25%	2123
March	1st to 10th	Night	15% 14% 4 9% 7% 6% 9% 4 4 4 23%	5373
	11th to 20th	Night	18% 16% 5% 11% 8% 6% 6% 4 5% 5% 18%	5089
	21st to end	Night	21% 17% 4 9% 9% 6% 3 2 3 4 22%	5587
April	1st to 10th	Night	19% 14% 4 9% 6% 5% 5% 4 4 5% 25%	2070
	11th to 20th	Night	20% 10% 3 7% 4 4 4 4 6% 5% 33%	1868
	21st to end	Night	20% 11% 3 7% 3 3 4 4 6% 5% 33%	1890
May	1st to 10th	Night	23% 12% 3 7% 4 3 4 3 5% 6% 30%	5225
	11th to 20th	Night	21% 9% 3 8% 4 4 4 4 4 6% 33%	4414
	21st to end	Night	18% 9% 3 9% 4 5% 5% 4 6% 6% 32%	4491
June	1st to 10th	Night	19% 9% 3 8% 5% 5% 4 4 6% 6% 32%	1470
	11th to 20th	Night	19% 7% 2 5% 4 4 5% 4 7% 7% 36%	1470
	21st to end	Night	21% 8% 3 9% 5% 5% 5% 4 5% 5% 29%	1470
July	1st to 10th	Night	12% 8% 3 8% 5% 5% 6% 4 7% 7% 35%	4110
	11th to 20th	Night	12% 6% 3 8% 6% 5% 6% 4 7% 9% 34%	4110
	21st to end	Night	9% 6% 2 7% 5% 5% 5% 5% 6% 8% 41%	4816
August	1st to 10th	Night	15% 6% 3 8% 5% 5% 5% 4 6% 7% 36%	3986
	11th to 20th	Night	11% 8% 4 9% 6% 6% 6% 5% 7% 8% 30%	4092
	21st to end	Night	14% 6% 3 6% 4 4 5% 3 6% 6% 43%	4531
September	1st to 10th	Night	17% 7% 2 6% 4 5% 5% 3 5% 7% 41%	2067
	11th to 20th	Night	15% 7% 2 6% 5% 5% 5% 3 5% 6% 41%	2310
	21st to end	Night	16% 6% 3 5% 4 5% 4 3 4 6% 46%	2289
October	1st to 10th	Night	18% 7% 2 6% 4 4 4 3 5% 6% 40%	2340
	11th to 20th	Night	21% 10% 3 7% 5% 5% 5% 4 5% 6% 29%	2420
	21st to end	Night	19% 13% 3 8% 4 5% 5% 4 6% 7% 26%	2860
November	1st to 10th	Night	19% 12% 4 9% 5% 5% 5% 4 5% 6% 25%	2782
	11th to 20th	Night	17% 15% 5% 12% 5% 5% 6% 3 4 6% 21%	2940
	21st to end	Night	17% 16% 5% 15% 8% 7% 5% 4 5% 4 14%	3000
December	1st to 10th	Night	12% 14% 5% 15% 12% 8% 7% 5% 5% 4 15%	5060
	11th to 20th	Night	17% 13% 4 14% 15% 7% 5% 4 4 4 13%	5741
	21st to end	Night	13% 14% 5% 13% 10% 10% 5% 4 5% 7% 14%	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	86% 3 5% 5% 1	4094
	11th to 20th	Day	81% 4 6% 6% 3	4338
	21st to end	Day	66% 6% 8% 12% 7%	5124
February	1st to 10th	Day	66% 3 9% 15% 6% 1	1838
	11th to 20th	Day	72% 3 8% 12% 4	1851
	21st to end	Day	65% 2 6% 19% 6%	1679
March	1st to 10th	Day	70% 2 9% 13% 5%	4691
	11th to 20th	Day	69% 5% 9% 14% 4	5090
	21st to end	Day	69% 2 5% 15% 8% 1	5587
April	1st to 10th	Day	63% 2 8% 16% 9% 2	2546
	11th to 20th	Day	56% 2 9% 22% 10% 1	2702
	21st to end	Day	59% 2 8% 18% 11% 2	2730
May	1st to 10th	Day	63% 3 8% 16% 9% 1	7686
	11th to 20th	Day	55% 5% 12% 19% 8% 1	8535
	21st to end	Day	57% 3 7% 18% 13%	9717
June	1st to 10th	Day	56% 3 9% 20% 11% 2	3150
	11th to 20th	Day	50% 5% 13% 19% 12% 2	3150
	21st to end	Day	58% 5% 11% 16% 9% 1	3150
July	1st to 10th	Day	46% 6% 14% 24% 10%	8805
	11th to 20th	Day	49% 8% 17% 21% 5%	8799
	21st to end	Day	42% 7% 20% 24% 7%	9068
August	1st to 10th	Day	48% 5% 19% 22% 6%	6102
	11th to 20th	Day	51% 8% 19% 18% 4	5992
	21st to end	Day	45% 7% 16% 24% 8%	6594
September	1st to 10th	Day	49% 3 15% 23% 9%	2550
	11th to 20th	Day	45% 4 15% 27% 9% 1	2310
	21st to end	Day	49% 4 11% 25% 10% 1	2288
October	1st to 10th	Day	54% 5% 15% 20% 6% 1	3345
	11th to 20th	Day	61% 3 12% 20% 4	3194
	21st to end	Day	58% 5% 14% 17% 6%	3180
November	1st to 10th	Day	67% 3 12% 13% 5%	1735
	11th to 20th	Day	73% 3 9% 11% 3	1680
	21st to end	Day	78% 2 10% 8% 2	1617
December	1st to 10th	Day	78% 4 9% 8% 1	2350
	11th to 20th	Day	75% 2 6% 11% 5%	2688
	21st to end	Day	75% 3 7% 9% 6%	3553
January	1st to 10th	Night	84% 3 7% 6% 1	8831
	11th to 20th	Night	77% 4 6% 9% 4	8623
	21st to end	Night	65% 5% 9% 13% 8%	9057
February	1st to 10th	Night	64% 4 7% 16% 7% 1	2781
	11th to 20th	Night	67% 3 10% 14% 6%	2666
	21st to end	Night	61% 3 9% 18% 9%	2123
March	1st to 10th	Night	66% 2 10% 14% 8%	5382
	11th to 20th	Night	69% 4 9% 12% 5%	5090
	21st to end	Night	69% 2 6% 13% 9% 1	5587
April	1st to 10th	Night	63% 2 7% 14% 12% 1	2070
	11th to 20th	Night	54% 2 7% 21% 14% 1	1868
	21st to end	Night	52% 3 8% 22% 14% 1	1890
May	1st to 10th	Night	57% 2 9% 17% 13% 1	5231
	11th to 20th	Night	54% 3 9% 22% 11% 1	4415
	21st to end	Night	53% 4 8% 20% 13% 1	4492
June	1st to 10th	Night	51% 4 10% 22% 12% 1	1470
	11th to 20th	Night	46% 5% 13% 21% 15% 1	1470
	21st to end	Night	56% 5% 11% 17% 10% 1	1470
July	1st to 10th	Night	46% 7% 14% 25% 8%	4075
	11th to 20th	Night	46% 8% 20% 23% 3	4068
	21st to end	Night	39% 8% 22% 23% 8%	4705
August	1st to 10th	Night	47% 6% 18% 22% 7%	3976
	11th to 20th	Night	49% 9% 23% 15% 4	4119
	21st to end	Night	41% 7% 16% 25% 11%	4531
September	1st to 10th	Night	46% 3 14% 29% 9%	2067
	11th to 20th	Night	45% 4 16% 24% 10%	2310
	21st to end	Night	42% 3 11% 26% 16% 1	2289
October	1st to 10th	Night	50% 3 11% 27% 7% 1	3821
	11th to 20th	Night	54% 4 13% 25% 4	3931
	21st to end	Night	54% 6% 15% 19% 5% 1	4610
November	1st to 10th	Night	61% 3 14% 15% 6%	2782
	11th to 20th	Night	69% 3 10% 13% 4	2940
	21st to end	Night	76% 4 9% 8% 3 1	3000
December	1st to 10th	Night	75% 4 11% 9% 1	5060
	11th to 20th	Night	77% 4 6% 9% 3	5742
	21st to end	Night	73% 3 9% 11% 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	27% 21% 27% 20% 4 1	220
	11th to 20th	Day	24% 22% 27% 14% 10% 4	220
	21st to end	Day	12% 23% 34% 23% 5% 3	242
February	1st to 10th	Day	20% 17% 31% 20% 8% 4	378
	11th to 20th	Day	18% 23% 33% 18% 7% 1	426
	21st to end	Day	22% 19% 32% 18% 7% 1	420
March	1st to 10th	Day	23% 19% 32% 20% 6% 1	540
	11th to 20th	Day	29% 18% 26% 18% 8% 1	540
	21st to end	Day	28% 17% 27% 18% 8% 3	594
April	1st to 10th	Day	30% 20% 26% 16% 7% 1	540
	11th to 20th	Day	28% 15% 31% 17% 7% 2	532
	21st to end	Day	33% 13% 25% 20% 7% 2	540
May	1st to 10th	Day	34% 12% 28% 19% 5% 2	552
	11th to 20th	Day	27% 13% 26% 22% 10% 2	774
	21st to end	Day	31% 15% 24% 20% 9% 2	845
June	1st to 10th	Day	28% 12% 24% 24% 9% 2	780
	11th to 20th	Day	26% 13% 25% 21% 13% 2	780
	21st to end	Day	25% 9% 26% 26% 10% 3	780
July	1st to 10th	Day	21% 6% 30% 28% 13% 3	770
	11th to 20th	Day	18% 10% 29% 29% 12% 2	768
	21st to end	Day	18% 9% 28% 29% 13% 3	720
August	1st to 10th	Day	17% 9% 28% 27% 14% 5%	566
	11th to 20th	Day	17% 9% 28% 29% 14% 3	559
	21st to end	Day	22% 9% 29% 24% 12% 5%	627
September	1st to 10th	Day	22% 13% 28% 21% 12% 5%	570
	11th to 20th	Day	24% 12% 28% 21% 11% 5%	570
	21st to end	Day	25% 14% 25% 19% 13% 6%	562
October	1st to 10th	Day	21% 13% 28% 21% 14% 4	452
	11th to 20th	Day	34% 10% 22% 19% 10% 5%	420
	21st to end	Day	34% 16% 21% 18% 10% 1	462
November	1st to 10th	Day	32% 17% 27% 18% 5% 1	425
	11th to 20th	Day	28% 16% 28% 19% 8%	430
	21st to end	Day	35% 20% 23% 16% 5% 1	367
December	1st to 10th	Day	23% 15% 36% 14% 8% 4	220
	11th to 20th	Day	26% 27% 28% 16% 3	220
	21st to end	Day	24% 24% 31% 14% 7% 1	242
January	1st to 10th	Night	22% 13% 30% 28% 6% 1	950
	11th to 20th	Night	23% 15% 29% 26% 7%	903
	21st to end	Night	15% 17% 30% 28% 10% 1	924
February	1st to 10th	Night	16% 14% 31% 29% 8% 2	840
	11th to 20th	Night	23% 12% 32% 23% 9%	823
	21st to end	Night	17% 11% 33% 28% 10% 1	692
March	1st to 10th	Night	23% 11% 30% 29% 6% 1	840
	11th to 20th	Night	26% 14% 27% 22% 9% 1	840
	21st to end	Night	24% 12% 26% 27% 10% 1	924
April	1st to 10th	Night	29% 15% 25% 25% 6%	755
	11th to 20th	Night	26% 12% 24% 28% 8% 1	624
	21st to end	Night	27% 13% 25% 26% 8% 1	630
May	1st to 10th	Night	29% 10% 24% 29% 8% 1	630
	11th to 20th	Night	23% 10% 26% 29% 11% 1	535
	21st to end	Night	22% 8% 27% 33% 10%	455
June	1st to 10th	Night	21% 6% 21% 41% 11%	420
	11th to 20th	Night	22% 5% 23% 34% 15% 1	420
	21st to end	Night	22% 6% 25% 34% 12% 1	420
July	1st to 10th	Night	20% 5% 23% 36% 16% 1	410
	11th to 20th	Night	17% 4 23% 41% 15%	408
	21st to end	Night	16% 6% 18% 39% 19% 1	460
August	1st to 10th	Night	16% 3 20% 38% 21% 1	556
	11th to 20th	Night	18% 4 16% 40% 21% 1	622
	21st to end	Night	18% 4 22% 35% 18% 2	693
September	1st to 10th	Night	22% 6% 26% 33% 12% 1	686
	11th to 20th	Night	21% 8% 22% 33% 16% 2	840
	21st to end	Night	20% 8% 26% 31% 14% 1	833
October	1st to 10th	Night	23% 11% 24% 30% 11% 1	800
	11th to 20th	Night	28% 8% 25% 25% 13% 1	800
	21st to end	Night	29% 14% 23% 24% 8% 1	880
November	1st to 10th	Night	30% 13% 24% 26% 6% 1	881
	11th to 20th	Night	29% 15% 26% 23% 6% 1	950
	21st to end	Night	30% 14% 26% 23% 7% 1	950
December	1st to 10th	Night	27% 12% 29% 25% 7% 1	950
	11th to 20th	Night	28% 19% 26% 21% 6%	950
	21st to end	Night	26% 17% 25% 23% 7% 2	1045

Page generated at 2026-09-26 04:18:43. Version ac07

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