High wispy clouds that look like tufts of white hair.
Precipitation Chance: Very Low
High-level clouds that form a wavy sheet. The sheet is composed of small dots which almost look two-dimensional.
A high cloud that covers the sky. It is transparent and typically causes a halo to form around the sun.
Mid-level puffy clouds that look like cotton balls. They are typically white with dark patches below and can be spaced out or sheet-like.
A mid-level cloud that covers the sky. The sun can barely be seen as a bright patch.
Precipitation Chance: Low
Expected Weather: Rain, Sleet, Snow, Ice Pellets
A mid-level cloud that is dark gray and covers the sky. It may be raining.
Precipitation Chance: Very High
Expected Weather: Rain, Snow, Ice Pellets
A low cloud that covers the sky. Objects don't cast shadows and it may be foggy.
Expected Weather: Fog, Haze, Drizzle, Snow, Snow Grains
Low clouds that look like a sheet of cotton balls with small gaps. The color ranges from white to dark gray.
Expected Weather: Rain, Drizzle, Snow, Snow Pellets
Low puffy clouds that look like cotton balls. They are spaced out and are typically white with darker patches below.
Expected Weather: Rain, Snow, Snow Pellets
Low puffy clouds that are very tall. They typically have an anvil shape and are dark.
Expected Weather: Rain, Heavy Rain, Snow, Snow Pellets, Hail, Lightning
This is a weather station made using a Raspberry Pi computer. It collects data from various sensors and logs that data every 5 minutes. The Raspberry Pi also hosts this web-page so that the data can be easily viewed.
It is possible to look through all collected historical data by creating custom charts on the historical data page.
Following is a list of parts that were used in this project. This is not an endorsement or recommendation for any product.
A Raspberry Pi 3B+ is what was used for this station. Any Raspberry Pi computer should be sufficient to make your own weather station. Because the web server runs on the Raspberry Pi, you may wish to have the latest/fastest Pi for better performance.
Link: https://www.raspberrypi.org/products/
The BME680 is an environmental sensor made by Bosch. It can sense temperature, humidity, barometric pressure, and VOC. The sensor can communicate over I2C or SPI.
Link: https://www.adafruit.com/product/3660
This station uses wind and rain sensors sold by Argent Data Systems. This includes an anemometer, a wind vane, and a rain gauge. The sensors are surprisingly simple; all of them make use of magnets and reed switches. Other vendors sell similar sets of sensors.
Link: https://www.argentdata.com/catalog/product_info.php?products_id=145
The DS18B20 is a digital temperature sensor that uses the 1-Wire interface. It is available in many forms. The one used in this station is waterproof and is sold by Adafruit. In this weather station, the sensor is used to measure the temperature an inch or so underground to get a better idea of the risk of frost.
Link: https://www.adafruit.com/product/381
The MCP3008 is an 8-Channel 10-Bit ADC that communicates over the SPI bus. In this project, it is used to measure data from the wind vane.
Link: https://www.adafruit.com/product/856
A convenient prototyping board made by Adafruit for the Raspberry Pi. It plugs into the GPIO header for the Raspberry Pi and sits neatly on top of it. It was used to make a clean and compact assembly for this project.
Link: https://www.adafruit.com/product/2310
2021-03-10: Station placed outside for the first time.
2022-06-01: Extention cord failed, experimenting with other ways to power the station.
2022-10-24: Station is now reliably solar powered.
2023-11-13: Raised wind vane and anemometer about 3 inches to allow them to catch more wind (although it is still below the fence line, unfortunately). Lowered rain gauge about 6 inches to prevent spurious readings caused by the wind shaking the rain gauge.
2023-11-19: Repaired some hail damage. Pressure readings erratic now. (Barometer seems broken)
2024-01-21: Updated to 64-bit OS. Moon calendar can now handle dates from February 0001 to November 9999.
2024-01-23: Replaced faulty pressure sensor. Added a hardware RTC.
2024-05-27: Wind and rain data unavailable due to an incident with a string trimmer.
The angle between the Sun, Moon, and Earth determines the amount of sunlight that can get reflected off the Moon into our eyes standing here on Earth. (The Moon does not produce any light of its own.) This angle changes over time as the Moon orbits Earth and Earth orbits the Sun.
As such, we see the Moon's disk shift from appearing totally dark to appearing fully lit and back to being dark again. The time it takes for this to happen is called a lunation, lunar cycle, or a synodic month. The total amount of time this takes varies because the Moon's orbit around Earth is not perfectly circular, and the Earth's orbit around the Sun is also not perfectly circular, but on average, a lunar cycle is 29.53059 days.
For the purposes of describing and keeping track of this cycle, astronomers have split it up into four primary, and four secondary Moon phases. The primary Moon phases are New Moon, First Quarter, Full Moon, and Third Quarter (also called Last Quarter). The secondary Moon phases are described as either waxing if the Moon is becoming more illuminated or waning if it is becoming less illuminated. Then the shape is described as either crescent if the moon is less than 50% illuminated or gibbous if the Moon is more than 50% illuminated. So the four secondary Moon Phases are Waxing Crescent, Waxing Gibbous, Waning Gibbous, and Waning Crescent. The primary phases occur at specific moments in time that are the same no matter where you are on Earth. The secondary phases instead represent a time-span in between the primary phases.
This phase is called new because it marks the beginning of a new lunar cycle. This phase occurs at the point in the moon's orbit when it is on the same side of the earth as the sun (Sun→Moon→Earth). The specific time it occurs is when the Moon and Sun are closest to each other in the sky (that is, they are in conjunction). From our point of view on Earth, the disk of the Moon will seem totally dark because we are facing the shadowed side of the Moon, which is not receiving any direct sunlight. If we could see the other side of the Moon (i.e. face the Earth from between the sun and the Earth) it would be totally illuminated.
Sometimes, when the new Moon's position lines up directly between the Sun and our point of view, the Moon will block out part or all of the Sun, causing a solar eclipse. Solar eclipses are only visible from a small portion of the Earth at a time.
This phase occurs for the time-span after the new Moon and before the first quarter. When viewed from the Northern Hemisphere of Earth, the crescent-shaped illuminated section of the Moon will appear on the right side of its surface. The illuminated area, which starts off very thin, will grow each day until the Moon reaches its first quarter, when the entire right half of the moon will appear illuminated. (In the Southern Hemisphere the waxing Moon phases appear to grow from the left side of the moon instead of the right, and from the equator it appears to grow from the top.)
This is the first phase in which half of the Moon's surface is illuminated. So why isn't it called a Half Moon? Well, it gets its name from the fact that at this phase, the Moon has traveled exactly ¼ of the way through a complete orbit around the Earth. It can be confusing because from our perspective, ½ the lunar surface appears lit. Some people do, in fact, refer to the quarter phases of the moon as a Half Moon, however, this is not an astronomical term. When viewed from the Northern Hemisphere, the right half of the Moon appears lit, while from the Southern Hemisphere, it is the left half of the Moon that appears lit. If you view the moon from on the equator, it is the top half of the Moon's surface that will be illuminated.
During the first quarter, the Moon is seen 90 degrees east of the Sun, this is called being at east quadrature.
If you're a beginning astronomer trying to view the Moon's surface, the quarter phases are the best time to see details. You might think the Full Moon is the best time to take in the lunar landscape, but when the sun shines straight down on the Moon's surface, it tends to eliminate all highlights and shadows. The best place to see details on the Moon's surface is right on the terminator (the day-night line) and during the quarter phases the terminator is directly facing us.
After the first quarter, and before the Full Moon, is when we see this phase. At the start of this phase you will see the right half of the Moon fully illuminated plus a small sliver of light extending into the left half of the Moon's surface. Every day, you will see more of the left half of the moon get covered in light until the Full Moon, when the entire Moon's surface will appear lit. In the Southern Hemisphere, this happens from left to right, and from the equator it happens from top to bottom.
The word Gibbous comes from the Latin word gibbus which meant "a hump, or a hunch" or as an adjective meant "bulging." In late Latin, this word was used to mean "hunchbacked." For this Moon phase, it is referring to the curved shape of the illuminated area on the Moon's surface.
This phase is named full because, from our point of view, the entire visible surface is illuminated. This phase occurs when the Moon and Sun are the farthest apart they can be from each other in the sky, on opposite sides of Earth (that is, they are in opposition). (Sun→Earth→Moon).
Sometimes, when the Earth's position lines up directly between the Sun and Moon, the Moon will enter Earth's shadow, cutting off some or all of the sunlight hitting the Moon's surface, causing a lunar eclipse.
Why is this phase named after how the Moon's surface appears to be lit, and the quarter phases named after their point in the Moon's orbit? Well, I'm not 100% sure, but I think it may be to distinguish which quarter you are talking about. If the quarter phases were both named Half Moon, it would leave ambiguity as to which part of the lunar cycle you are referring to.
This phase covers the time-span after a Full Moon and before the third quarter. During this phase, the Moon will begin mostly lit except for a small sliver of darkness on the right side (seen from the Northern Hemisphere). Every day that passes, the darkness will creep across the surface of the Moon until it reaches third quarter, when the Moon will be half illuminated. The darkness will begin increasing from the right when viewed in the Northern Hemisphere, and from the left when viewed in the Southern Hemisphere. When viewed from the equator, the dark shadow will creep down from the top.
This is the second phase in which half of the Moon's surface is illuminated. This phase occurs when the Moon has traveled exactly ¾ of the way through its orbit around Earth. The last quarter of the Moon's orbit begins with this phase, which is why it's often referred to as Last Quarter. When viewed from the Northern Hemisphere, the left side of the moon appears lit. When seen from the Southern Hemisphere, the right side of the moon appears lit, and when observed from the equator, the bottom half of the Moon will appear lit.
During the third quarter, the Moon is seen 90 degrees west of the Sun, this is called being at west quadrature.
This is the final phase in the lunar cycle before it begins anew. This phase occurs after third quarter until the next new Moon. When viewed from the Northern Hemisphere, this phase will start with the Moon's left side appearing almost fully lit, with just a bit of shadow creeping over the center from the right. The illuminated portion of the moon will slowly shrink every day during this phase until a new Moon is reached, when the Moon will be completely dark, and a new lunar cycle will begin. Viewing from the Southern Hemisphere, the same thing happens, only the illuminated portion of the surface will recede towards the right side of the Moon. Seen from the equator, the lit portion of the Moon will disappear towards the bottom side.
Ever heard the phrase "Once in a Blue Moon" and wondered what it was referring to? Me too. There are a few definitions floating around out there, but I don't think the most common ones are applicable to the original meaning of the phrase.
The most commonly used definition for a Blue Moon today refers to the second Full Moon in a calendar month. This is currently the only definition this site follows when it shows the current Moon Phase as Blue Moon. However, this definition seems to have appeared in the 1946 issue of Sky & Telescope magazine as a misunderstanding of an earlier definition written in the 1937 Maine Farmer's Almanac. This definition didn't really catch on, though, until the 1980s, when it was spread on a popular NPR program: Star Date. As for the phrase, this definition doesn't seem to fit as it occurs like clockwork every 2.7 years or 30 months on average.
So what was the definition used in the Maine Farmer's Almanac? Well, it spoke of an extra full moon in an astronomical season. Normally, when you look at the seasons as defined by the dates of the solstices and equinoxes, there are three Full Moons per season. Occasionally, however, there will be four Full Moons in a season. In such a case, the third Full Moon in a season that has four Full Moons is a Blue Moon. The Maine Farmer's Almanac had been using that definition since at least the early 1900s. Like many other farmer's almanacs, the Maine Farmer's Almanac used traditional Native American names for the Full Moons, which typically correspond to the season. For example, a Full Moon in January might be called a Wolf Moon, a Full Moon in February might be called a Snow Moon, and a Full Moon in March might be called a Worm Moon. To ensure these names match up with their associated season, the Blue Moon was invented to account for the case when there are four Full Moons in a season. This definition also occurs regularly, about once every 2 to 3 years.
Looking further back, texts from the 16th century suggest that the term blue Moon was used as an obvious absurdity. For example, one might say "He would argue that the Moon was blue," meaning he was arguing nonsense. By the 18th century, the meaning seems to have evolved to mean never. "I'll marry you, m'lady, when the Moon is blue!" would not have been taken as a betrothal.
In 1883, the Indonesian volcano, Krakatoa, exploded violently and produced the loudest sound ever recorded. People 3,000 miles (about 4,828 km) away described the sound as being like cannon fire. The explosion caused ⅔ of the island to collapse and triggered tsunami waves across the Indian Ocean that rocked ships in South Africa. The explosion was estimated to be equivalent to about 200 megatons of TNT (approximately 13,000 times the yield of the Little Boy nuclear bomb dropped on Hiroshima and around 4 times the yield of the largest nuclear bomb ever detonated). Needless to say, it was one of the most violent geological events in recorded history. It also spewed large amounts of particulate matter into the air which had many effects, but notably here, it turned the Moon visibly blue (and sunsets green) across the globe for nearly two years. A rare event indeed; I believe this event made most people realize the moon could, in fact, appear blue, and so the meaning shifted to be a very rare occurrence.
The blue Moon, of course, is also sometimes used as a symbol of sadness and loneliness. There are doubtless countless other meanings that have been used over time, but this is what my research has shown for the popular uses of the term Blue Moon.
Below are some general guidelines for when you can see the Moon. The four primary Moon phases (in italics) rise and set at specific times; the secondary phases fall into a more broad span of time.
