Sizes:

Average High and Low Temperatures (table sorted by)
Humidity Comfort Levels
By dew point: dry < 55°F < comfortable < 60°F < humid <
65°F < muggy < 70°F < oppressive < 75°F < miserable
Average Monthly Rainfall Daily Chance of Precipitation to the Dollar
Rising is good - ie. $1 buys more of the local currency
Granada 202'
wet season is overcast, the dry season is windy and partly cloudy, and it is hot and oppressive year round.
Typically 71°F - 93°F
Rarely <68°F | >96°F

Source
 
COL: You would need around $2,132 in Managua to maintain the same standard of life that you can have with $4,100 in Fort Myers, FL (assuming you rent in both cities).  Source
Source
Arequipa 7600'
has a cold desert climate.
Typically 48°F - 73°F
Rarely <44°F | >76°F

Source
 
COL: You would need around $1,865 in Arequipa to maintain the same standard of life that you can have with $4,100 in Fort Myers, FL (assuming you rent in both cities).
Source
Source
Cuenca 8400'
has a mild humid temperate climate with warm summers & no dry season.
Typically 44°F - 63°F
Rarely <40°F | >67°F

 
 
 
  The Ecuador dollar is
pegged to the US dollar
Medellín 4900'
has a tropical rainforest climate with no dry season. Typically 62°F - 78°F
Rarely <58°F | >81°F

Source
 
COL: You would need around $1,532 in Medellin to maintain the same standard of life that you can have with $4,100 in Fort Myers, FL (assuming you rent in both cities).
Source
Source
Armenia 4860'
is warm and overcast.
Typically 61°F - 79°F
Rarely <57°F | >83°F
Source
Pereira 4630'
is warm and overcast.
Typically 61°F - 78°F
Rarely <58°F | >82°F
Source
Portimão '
summers are warm, arid, and mostly clear and the winters are long, cool, windy, and partly cloudy.
Typically 48°F - 81°F
Rarely <42°F | >89°F

 
COL:
You would need around $3,221 in Faro to maintain the same standard of life that you can have with $4,100 in Fort Myers, FL (assuming you rent in both cities). Source
Source
Jinotega 3000'
The wet season is muggy and overcast, the dry season is partly cloudy, and it is warm year round.
Typically 56°F - 84°F
Rarely <53°F | >88°F
Esteli 2770'
The wet season is muggy and overcast, the dry season is partly cloudy, and it is warm year round.
Typically 61°F - 88°F
Rarely <56°F | >91°F
San Isidro de El General 2297'
is warm, muggy, and overcast.
Typically 69°F - 85°F
Rarely <66°F | >87°F

 
COL:
You would need around $2,982 in San Jose to maintain the same standard of life that you can have with $4,100 in Fort Myers, FL (assuming you rent in both cities). Source
Source
Matagalpa 2300'
Typically 60°F - 87°F
Rarely <56°F | >91°F
Fort Myers '
the summers are long, hot, oppressive, wet, and mostly cloudy and the winters are short, comfortable, and mostly clear.
Typically 55°F - 91°F
Rarely <42°F | >94°F
Source

 
 
 
  The US dollar
Manta 0'
has a tropical climate with dry summers.
Typically 70°F - 83°F
Rarely <68°F | >86°F

 
 
 
  The Ecuador dollar is
pegged to the US dollar
Chiang Mai 1280'
The wet season is oppressive and overcast, the dry season is mostly clear, and it is hot year round.
Typically °59F - 97°F
Rarely <53°F | >102°F
Src

Source
Chiang Rai 1020'
The wet season is oppressive and overcast, the dry season is mostly clear, and it is hot year round.
Typically °56F - 94°F
Rarely <50°F | >100°F
Src

Source
Leon 280'
Typically 72°F - 94°F
Rarely <68°F | >97°F
David -20'
has a tropical savannah climate with dry winters.
Typically 76°F - 93°F
Rarely <74°F | >95°F

 
 
 
  The Panama dollar is
pegged to the US dollar
Kuala Lumpur 217'
is hot, oppressive, and overcast.
Typically 73°F - 91°F
Rarely <70°F | >94°F
Src

Source
George Town 46'
is hot, oppressive, and overcast.
Typically °75F - 89°F
Rarely <72°F | >92°F
Src

Source
The weather plots are from https://weatherspark.com/.
The currency plots are from http://www.xe.com/.
Cost of Living:

Source
 
 

First choices:

Colombia
2:00 / 2:15 drive Ft Myers to FLL / MIA
3:30 $160-200 nonstop to MDE
It is called the M-11. It can be valid for up to three years but recently is being granted for only a year, depending on your health insurance coverage. In 2020, you needed an income of only 2,633,409 pesos per month (US$703) to qualify. Source
Taxes  You become liable for filing income taxes the first year you reside in Colombia for over 183 days. Rates range from 10% to 35%. Based on the table on medellinguru.com (from 2016) copied below,
 I think I'd be in the 28% bracket and pay about $10,000 a year 
. I'd definitely limit my stays to 6 months - winters in FL, summers in Medellín?

 
It used to be that you were not taxed on worldwide income until you had been a tax resident (staying more than 183 days/yr) for five years. That changed in 2013. You now become liable for filing income taxes the first year you reside in Colombia for over 183 days. That is any 365-day period - not a calendar year. Source
Costa Rica
2:00 / 2:15 drive Ft Myers to FLL / MIA
3:00 $150 nonstop to SJO
The Persionado (temporary residency visa) requires proof of permanent monthly income of US$1,000.
The permit has a validity of 2 years, and may be renewed on condition that you still meet the requirements. For renewal, it must be proved that the income has been received in Costa Rica and you have lived in the country at least 4 months per year, continuous or discontinuous.
Pensionado Visa holders may establish a business or work on their own, but may not work as employees. Source Also
Taxes  An individual is tax resident in Costa Rica if she or he spends more than 6 months a year within the country.
Costa Rica levies income taxes on a territorial basis. This means that  both tax residents and non-residents are subject to tax only on their Costa Rican-source income  . Source
Insurance  You will be required to contribute to La Caja Costarricense de Seguro Social (C.C.S.S.) (Social Security Fund), acquiring a seguro voluntario (voluntary insurance). The cost will depend on the income received, but it is around 9-10% of the stated monthly income. Source
Panama
2:00 / 2:15 drive Ft Myers to FLL / MIA
3:00 $220-320 nonstop to PTY
6:30 $380 1-stop to DAV
Your pension must be at least $1,000 per month.
Other costs  Law requires a lawyer to submit all visa applications
Taxes  Panama has a territorial tax system, meaning that  it exempts all income earned outside Panama . Source
Benefits 
  • 50 percent off entertainment anywhere in the country including movies, theaters and concerts
  • 30 percent off bus, boat and train fares
  • 25 percent off airline tickets
  • 50 percent off hotel stays Monday through Thursday
  • 25 percent off hotel stays Friday through Sunday
  • 25 percent off at sit-down restaurants
  • 15 percent off at fast food restaurants
  • 15 percent off hospital bills (if no insurance applies)
  • 10 percent off prescription medications
  • 20 percent off medical consultations
  • 15 percent off dental and eye exams
  • 20 percent off professional and technical services
  • 50 percent off closing costs for home loans
Source
Peru
2:00 / 2:15 drive Ft Myers to FLL / MIA
5:45 $210 nonstop to LIM
9:40 $375 1-stop to AQP
The Rentista Visa is good for life and does not need to be renewed annually. There is only a small step each year that needs to be completed to basically prove that you are still in the country.
Expats with Rentista Visas do not need to pay the annual tax that is required from other foreigners. As well, they are  exonerated from paying any Peruvian Income Tax on their pension money . And personal and domestic items can be imported into the country duty and tax free. Source
This is a permanent visa to reside in the country and holds no expiry date however you will not be able to work on it. You are also permitted to import any personal items (including furniture) into Peru without having to pay tax on them. Please note this does not include a car, if you wish to import your car to Peru you will be liable for the usual taxes and duties.
 
On this visa you do not need to renew your carne de extranjeria (residence permit) every year and do not need to pay foreign tax. Source
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Taxes  No breaks for expats. All residents must pay an income tax of 15% up to 50,000 soles (about $17,000) earned anywhere in the world and  30%  for income over that amount. Source
All residents are taxed on income that they earn worldwide, while non-residents are taxed only on Peruvian earned income. For the purposes of taxation a resident is a Peruvian national or a foreign national that has spent more than  183 days  a year in the country. Source

Lesser choices:

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Nicaragua
Pros  The major benefits of the program come in the form of tax incentives. As a foreign retiree, you're entitled to:
  •  Pay no taxes on any out-of-country earnings 
  • Residency for five years, with the ability to renew
  • Bring into Nicaragua up to US$20,000 worth of household goods for your own home, duty free
  • Pay no sales tax on purchase of $50,000 worth of products used to build your business
  • Import one automobile (value $25,000 or less) for personal or general use and pay no import tax or protective tariff and sell it after five years, again exempt from consumer sales tax
  • Import an additional vehicle every five years under the same duty exemptions.
Source
Cons  A foreign retiree "cannot work in any industrial or commercial activity or hold a job paid in local currency". But the Nicaraguan consulate in the United States assures us that the law is open to liberal interpretation. If you want to open a small hotel or restaurant, for example, an enterprise that would benefit the community in some way, say by attracting tourists or creating jobs, then you'd merely have to present your plan to the Ministry of Economy and Industry and ask for an exception to the rule. Source
Fees  At the time of writing (April 2015?), the fees for the temporary residence card (valid for 1 year) are C$2,000 ($65) and for a permanent residence card (valid for 5 years) C$5,000 ($160).
You'll also have costs for the certification and translation of documents. And since the application process typically lasts several months, be prepared to purchase extensions for your tourist visa for C$500 per 30 days, the so-called "prorroga".
If you enlist the help of a lawyer, expect to pay anything between US$300 and US$800 per person for his or her services. Source
Other Costs  Once you are a Nicaraguan resident, you must get the government's permission to leave the country, the so-called "visa de salida." Depending on how often you want to travel, you have the choice between purchasing a one-time exit visa C$200 ($6), or one that is valid for 3 months C$400 ($11), 6 months C$800 ($23) or one year C$1600 ($46). Source
Portugal
if you are in Portugal for 183 or more days in a single calendar year, you will typically be classed as a Portuguese tax resident. If you are classed as a tax resident, your worldwide income is subject to Portuguese income tax. This income could include salary, rental income and capital gains. Portugal has various tax treaties with other countries, including a tax treaty with the UK, which ensures that you should not have to pay tax more than once on any income in multiple jurisdictions. Source
 
United States and Portugal have an income tax treaty in place. The main purpose of a tax treaty is to ensure proper tax treatment of monies earned by US citizens, Portuguese citizens, ex-pats and residents of each other's country. Sourcs
Spain
Spain is famous for its bureaucracy, which can be particularly frustrating when it comes to understanding your tax obligations. Spain's tax system is complex, subject to change and differs from one autonomous region to another. The general rule is that you're considered a tax resident if you spend more than 183 days in Spain during the calendar year. You may also qualify as a tax resident if your main professional activity is based in Spain or if your spouse or dependent children are living in Spain. Income tax is progressive, and the rates for national and local income tax are usually between 19% and 48%. The sales tax is a 21% tax on consumer goods that is usually included in the price indicated on price stickers. Spain also has a wealth tax that is imposed annually and based on the total net worth of your worldwide assets and income. The rate is .2% to 2.5%, depending on the region where you're living. Each tax resident is allowed assets of 700,000 euros and a personal residence worth 300,000 euros. However, no wealth tax is imposed by the Madrid autonomous region.
Malaysia
Benefits 
  •  Foreign-source income is not taxable in   Malaysia. 
  • Can work part-time (20 hr/week).
  • Import personal / household items, tax exempted
  • Invest in local companies, share market & unit trusts
  • Interest gained from bank fixed deposit is tax exempted
  • Each participant is allowed to bring in a personal car. The vat (GST) tax exemption when buying a new car in Malaysia ended Apr 1, 2015.
  • Each participant is permitted to purchase residential houses at a minimum price above MYR 1,000,000 ($259,000) each such as Kuala Lumpur and Penang that are pre-approved by the Foreign Investment Committee of Malaysia. MYR 500,000 ($129,000)?
  • 10 years + renew for life
  • No minimum stay in Malaysia - come & go as you please
  • Tropical Temperature Year Round 75 - 90° F /
    Hill Resorts 54 - 68° F
  • Quality Low Living Cost - From $15-25/day ($300-750/mo)
  • One mo 2 BR Service Apartment from $700/mo
    Yr long 3 BR Condominium from $600/mo
  • Good Modern Infrastructure - Roads / Air Links / 1st Class Medical Facilities
Requirements 
  • Show that they have sufficient funds to maintain themselves for the duration of the 10-year visa. In practice, this means showing at least MYR150,000  ($38,000) in the bank  and MYR10,000  ($2,550) monthly income. After a period of one year, the participant who fulfills the fixed deposit criteria can withdraw up to MYR50,000.00 ($13,000) for approved expenses relating to house purchase, education for children in Malaysia and medical purposes. However, a minimum balance of MYR100,000.00  ($25,500) maintained  from the second year onwards and throughout stay in Malaysia under this program.
  • All applicants and their dependents (spouse and children) are required to submit a medical report from any private hospital in Malaysia.
  • Medical insurance 2252-4399RM/yr  ($580-1133).
Vietnam
Tax Basis - Vietnamese residents are taxed on their worldwide income; nonresidents are taxed only on Vietnamese-source income.
 
Residence - An individual is resident if he/she: (1) spends 183 days or more in the aggregate in a 12-month period in Vietnam starting from the date the individual arrives in Vietnam; (2) maintains a residence in Vietnam; or (3) has leased a residence for 90 days or more in a tax year.
Thailand
The retirement visa lasts for a year and you can renew it without leaving the country. To qualify, you should have at least $26,000 in your bank account, or deposits + annual income > $26,000. You need to report to the immigration police every 90 days while staying in Thailand. You should also note that you need to apply for a re-entry permit if you want to leave Thailand and return before your retirement visa expires.
Best option is to apply for the Non Immigrant O-A visa before they make their way to Thailand. This visa is has multiple entry and is valid for 1 year. Each entry they would get 1 of Admitted to Stay, so they can get almost 2 years of stay out of this visa. For travelling during the second year they need a re-entry permit. Source
Other references: