Amarillo
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Amarillo clear sky chart from 2005-11-05 to 2018-01-12.

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 TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(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

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
49%
16243
32%
48082
18%
16197
61%
16197
46%
24802

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 15thNight
45%
956
32%
2472
14%
951
57%
951
50%
1317
January16th to endNight
43%
831
39%
2367
17%
831
61%
831
52%
1171
February1st to 15thNight
39%
704
31%
2112
15%
700
54%
700
41%
1107
February16th to endNight
33%
632
35%
1894
12%
632
52%
632
42%
975
March1st to 15thNight
37%
719
31%
2159
15%
719
50%
719
42%
1123
March16th to endNight
31%
576
31%
2040
13%
576
54%
576
38%
991
April1st to 15thNight
27%
539
30%
1798
11%
539
50%
539
38%
913
April16th to endNight
28%
540
30%
1794
15%
540
52%
540
41%
890
May1st to 15thNight
38%
540
30%
1620
18%
540
57%
540
42%
855
May16th to endNight
44%
562
25%
1684
17%
561
57%
561
41%
920
June1st to 15thNight
47%
540
21%
1616
12%
540
58%
540
49%
803
June16th to endNight
60%
540
28%
1440
19%
540
68%
540
54%
758
July1st to 15thNight
71%
510
25%
1382
22%
510
74%
510
48%
765
July16th to endNight
82%
564
28%
1594
29%
531
83%
531
49%
817
August1st to 15thNight
77%
539
23%
1772
27%
536
79%
536
39%
935
August16th to endNight
74%
573
24%
1910
28%
573
76%
573
37%
1051
September1st to 15thNight
68%
540
25%
1867
25%
540
74%
540
36%
1013
September16th to endNight
61%
537
35%
1980
31%
537
72%
537
43%
917
October1st to 15thNight
46%
540
35%
1980
24%
540
61%
540
40%
955
October16th to endNight
56%
821
40%
2357
20%
821
68%
821
61%
1077
November1st to 15thNight
52%
950
35%
2470
15%
950
63%
950
60%
1226
November16th to endNight
48%
975
40%
2535
17%
975
61%
975
55%
1298
December1st to 15thNight
45%
975
34%
2535
14%
975
58%
975
47%
1389
December16th to endNight
38%
1040
36%
2704
15%
1040
52%
1040
44%
1536

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 ForecastData
Points
Cloud CoverDay
5%313323447%59%
49247
Night
5%313323347%61%
48270
Cloud CoverDay
5%313324447%59%
49245
Night
5%313323347%61%
48270
TransparencyDay
24%49%23%25%12%
48937
Night
22%49%22%26%15%
48083
SeeingDay
7%5%26%35%20%4
6026
Night
6%6%34%38%12%
16244

By Month

Percentage Cloud Cover SW (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
4313223337%62%
1710
16th to endDay
4313313235%66%
1866
February1st to 15thDay
5%5%2322233463%
1750
16th to endDay
4413313346%62%
1580
March1st to 15thDay
6%412323346%60%
1800
16th to endDay
6%323223235%62%
2181
April1st to 15thDay
6%31232335%5%60%
2150
16th to endDay
5%212323446%63%
2166
May1st to 15thDay
7%323323345%59%
2331
16th to endDay
431332335%8%58%
2430
June1st to 15thDay
331333446%8%56%
2340
16th to endDay
31232446%9%60%
2518
July1st to 15thDay
7%31432446%7%54%
2490
16th to endDay
32135%35%5%6%10%52%
2466
August1st to 15thDay
42134245%6%10%53%
2175
16th to endDay
6%4245%25%46%9%48%
2292
September1st to 15thDay
8%425%435%447%48%
2091
16th to endDay
6%313323346%62%
1980
October1st to 15thDay
8%31331333461%
1980
16th to endDay
322212226%72%
1851
November1st to 15thDay
1213323347%66%
1718
16th to endDay
6%21321222469%
1755
December1st to 15thDay
6%31332335%5%60%
1755
16th to endDay
6%6%34323335%57%
1872
January1st to 15thNight
4314223336%63%
2472
16th to endNight
4312313236%66%
2367
February1st to 15thNight
5%313423236%62%
2102
16th to endNight
6%313323437%59%
1894
March1st to 15thNight
5%42331335%5%61%
2159
16th to endNight
6%313323346%61%
2040
April1st to 15thNight
5%41332235%7%58%
1798
16th to endNight
6%21341245%5%61%
1794
May1st to 15thNight
5%312323445%62%
1619
16th to endNight
6%31222335%8%59%
1683
June1st to 15thNight
21123145%7%11%58%
1616
16th to endNight
21113346%10%61%
1440
July1st to 15thNight
331442345%10%56%
1464
16th to endNight
313325%46%11%56%
1702
August1st to 15thNight
3213335%7%7%11%50%
1782
16th to endNight
4323435%6%7%9%50%
1910
September1st to 15thNight
6%3144245%5%8%53%
1867
16th to endNight
6%312312447%62%
1980
October1st to 15thNight
6%41422232365%
1980
16th to endNight
3211212245%72%
2357
November1st to 15thNight
2212212345%70%
2470
16th to endNight
3312212336%68%
2535
December1st to 15thNight
5%413323246%61%
2535
16th to endNight
6%424322246%58%
2704

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
5%313223436%62%
1710
16th to endDay
4313313245%66%
1866
February1st to 15thDay
5%5%13213335%62%
1750
16th to endDay
4413323336%62%
1580
March1st to 15thDay
7%413413346%59%
1800
16th to endDay
6%42331333463%
2179
April1st to 15thDay
6%31231345%6%60%
2150
16th to endDay
5%21322335%6%62%
2166
May1st to 15thDay
7%332224345%59%
2331
16th to endDay
431332445%7%59%
2430
June1st to 15thDay
3313325%45%9%56%
2340
16th to endDay
31113245%6%9%60%
2518
July1st to 15thDay
7%32342445%7%55%
2490
16th to endDay
22135%25%6%6%9%53%
2466
August1st to 15thDay
4213325%5%6%10%53%
2175
16th to endDay
6%315%5%345%6%9%49%
2292
September1st to 15thDay
8%325%5%35%45%7%48%
2091
16th to endDay
6%31232345%6%62%
1980
October1st to 15thDay
9%21322333462%
1980
16th to endDay
3212212235%72%
1851
November1st to 15thDay
1213323347%66%
1718
16th to endDay
6%31321222469%
1755
December1st to 15thDay
6%3332335%5%61%
1755
16th to endDay
6%7%24323335%56%
1872
January1st to 15thNight
4313223336%63%
2472
16th to endNight
5%222223236%66%
2367
February1st to 15thNight
5%413424236%62%
2102
16th to endNight
6%313323447%59%
1894
March1st to 15thNight
5%413323345%60%
2159
16th to endNight
6%313323335%62%
2040
April1st to 15thNight
6%41232346%7%58%
1798
16th to endNight
6%31332345%5%61%
1794
May1st to 15thNight
5%322324445%62%
1619
16th to endNight
6%21321435%7%59%
1683
June1st to 15thNight
31132447%11%58%
1616
16th to endNight
21122446%10%61%
1440
July1st to 15thNight
331432445%10%56%
1464
16th to endNight
3123346%6%11%56%
1702
August1st to 15thNight
32134346%8%11%50%
1782
16th to endNight
4213425%6%7%9%50%
1910
September1st to 15thNight
6%3233245%6%9%52%
1867
16th to endNight
6%212213347%62%
1980
October1st to 15thNight
6%31431223365%
1980
16th to endNight
312212236%72%
2357
November1st to 15thNight
231213346%70%
2470
16th to endNight
3212222236%68%
2535
December1st to 15thNight
5%41322335%6%61%
2535
16th to endNight
6%424422235%59%
2704

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
22%27%28%28%9%
1711
16th to endDay
21%26%23%33%12%
1866
February1st to 15thDay
24%28%24%26%13%
1751
16th to endDay
23%25%23%31%14%
1580
March1st to 15thDay
25%26%20%31%13%
1800
16th to endDay
24%27%24%24%16%
2181
April1st to 15thDay
24%36%16%28%19%
2150
16th to endDay
21%310%21%27%15%
2166
May1st to 15thDay
26%48%20%23%16%
2331
16th to endDay
24%410%21%23%15%
2434
June1st to 15thDay
24%412%23%19%14%
2340
16th to endDay
19%5%11%26%21%15%
2518
July1st to 15thDay
26%6%11%24%21%8%
2343
16th to endDay
25%6%14%29%20%4
2311
August1st to 15thDay
22%7%16%28%18%5%
2161
16th to endDay
29%6%11%24%21%6%
2292
September1st to 15thDay
33%6%12%24%16%6%
2091
16th to endDay
22%48%25%28%10%
1980
October1st to 15thDay
26%48%20%28%12%
1980
16th to endDay
15%26%21%37%17%
1851
November1st to 15thDay
17%37%20%35%16%
1718
16th to endDay
20%1419%33%20%
1755
December1st to 15thDay
23%210%28%26%9%
1755
16th to endDay
30%26%25%24%10%
1872
January1st to 15thNight
21%28%24%32%11%
2472
16th to endNight
20%26%22%32%16%
2367
February1st to 15thNight
26%26%21%27%15%
2112
16th to endNight
24%25%20%26%19%
1894
March1st to 15thNight
24%25%21%28%16%
2159
16th to endNight
24%38%25%19%19%
2040
April1st to 15thNight
24%49%20%22%19%
1798
16th to endNight
21%5%9%21%24%16%
1794
May1st to 15thNight
23%5%8%15%26%19%
1620
16th to endNight
24%7%11%17%20%18%
1685
June1st to 15thNight
17%6%19%23%18%14%
1616
16th to endNight
16%7%14%27%18%16%
1440
July1st to 15thNight
22%6%12%26%22%9%
1382
16th to endNight
20%5%15%29%23%5%
1594
August1st to 15thNight
22%9%18%23%17%9%
1772
16th to endNight
26%8%13%26%20%5%
1910
September1st to 15thNight
27%6%13%28%14%8%
1867
16th to endNight
20%410%23%29%11%
1980
October1st to 15thNight
24%39%17%25%18%
1980
16th to endNight
13%26%19%38%19%
2357
November1st to 15thNight
15%27%21%33%19%
2470
16th to endNight
17%2321%32%22%
2535
December1st to 15thNight
23%37%23%28%13%
2535
16th to endNight
27%27%21%29%11%
2704

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
13%7%28%34%15%
123
16th to endDay
7%6%42%31%9%3
96
February1st to 15thDay
8%10%32%25%21%2
90
16th to endDay
38%39%37%9%1
81
March1st to 15thDay
6%434%44%10%
90
16th to endDay
7%13%33%30%13%
165
April1st to 15thDay
11%16%39%25%7%
269
16th to endDay
8%18%40%26%5%1
276
May1st to 15thDay
8%10%34%33%11%
468
16th to endDay
9%6%35%31%14%2
517
June1st to 15thDay
4330%40%16%3
495
16th to endDay
4123%35%27%7%
495
July1st to 15thDay
8%110%41%29%8%
475
16th to endDay
26%38%40%11%
515
August1st to 15thDay
5%10%40%34%7%
330
16th to endDay
7%113%41%26%9%
332
September1st to 15thDay
3113%46%26%8%
246
16th to endDay
10%220%32%26%6%
135
October1st to 15thDay
7%235%38%11%3
135
16th to endDay
25%31%34%21%4
144
November1st to 15thDay
5%433%37%12%7%
135
16th to endDay
12%16%26%28%13%2
135
December1st to 15thDay
5%440%36%12%1
135
16th to endDay
12%9%46%22%9%
144
January1st to 15thNight
5%7%36%39%10%
956
16th to endNight
6%6%41%35%10%
831
February1st to 15thNight
7%10%40%34%6%
704
16th to endNight
8%9%46%30%4
632
March1st to 15thNight
8%9%41%35%5%
719
16th to endNight
7%12%46%28%5%
576
April1st to 15thNight
7%12%50%26%2
539
16th to endNight
7%10%51%26%3
540
May1st to 15thNight
7%8%44%31%9%
540
16th to endNight
8%6%40%35%9%
563
June1st to 15thNight
45%40%42%7%
540
16th to endNight
2134%45%16%
540
July1st to 15thNight
316%57%21%
510
16th to endNight
38%54%32%
564
August1st to 15thNight
49%53%30%1
539
16th to endNight
4112%50%28%2
573
September1st to 15thNight
7%16%52%21%1
540
16th to endNight
8%224%42%19%1
537
October1st to 15thNight
10%5%35%38%9%1
540
16th to endNight
45%31%38%17%1
821
November1st to 15thNight
45%34%38%16%
950
16th to endNight
5%8%35%36%14%
975
December1st to 15thNight
7%8%36%37%10%1
975
16th to endNight
9%8%40%33%8%
1040
Page generated at 2018-01-12 21:01:26. Version ac04

Copyright 2018 A. Danko


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